Home Posts Tagged "phalaenopsis"


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At the end of the 1970s, the Overgaag family, with a background in vegetable growing, emigrated from the Netherlands to California to start a new nursery. Westerlay Orchids thrived and has now evolved into one of the preeminent orchid growers in the United States. The company has seen significant growth in recent years in particular, as American consumers are increasingly developing a real feel and passion for phalaenopsis. The focus is currently on optimising operational management, but the grower remains on the lookout for new opportunities in the market.

The region surrounding the city of Carpinteria forms the heart of horticultural production in California. The area, which is part of Santa Barbara County, is home to fields and greenhouses that stretch as far as the eye can see, bursting with fruit, vegetables and flowers. “There’s also been a rise in cannabis growing for medicinal purposes here,” says Toine Overgaag. He has been President of Westerlay Orchids for some years.
The company’s name refers to the former Westerlee auction in the Westland region of the Netherlands. The roots of the family can be found there. “My grandfather was a tomato grower in ‘s Gravenzande, and my dad and uncle switched to growing chrysanthemums later,” he says. “But two captains on one ship wasn’t ideal, so in 1978 my parents decided to cross the pond to the USA.”

Dot com bubble

To keep a long story short: Joop and Lucia Overgaag started growing cut hybrid tea roses in Carpinteria, initially on 1.5 hectares but expanding in later years. To begin with it wasn’t on the cards that Toine Overgaag would take over the family business. “After graduating I worked as a management consultant in Los Angeles for a few years. When the dot com bubble burst in around 2000, I lost my job. I decided to start working for my parents for a while and enjoyed it so much, I made my temporary move a permanent one. The fact that my father wanted to shift the company’s focus to growing other plants was also a strong draw. At the time competition from roses sourced from Colombia and Ecuador was getting bigger, which pressured the prices. I saw growing a new crop as a challenging opportunity.”

Learning curve

The family decided to switch from roses to orchids. In 2002 they started growing potted cymbidiums. “An advantage of orchids is they are more complicated to bring in from abroad,” he says. “So we reckoned there would be less competition. Orchid growing is also highly capital intensive, so it’s not open to everyone. And on top of that, through the intervention of a small-scale Australian grower, we were given the chance to start with a special selection of potted cymbidiums.”
The grower admits that the transition, although gradual, was not without its bumps and victories. In the early days, supplying a high-quality product was difficult. “That was primarily down to our lack of experience with orchid growing and the often poor quality of the planting material we had to work with. To sum it up, it was a steep learning curve.”
Tapping into the market also took some effort. “We sold our roses to wholesalers, but those customers hardly did any business with potted cymbidiums. So we had to go knocking on doors with our flowers and it took some time to get supermarkets enthusiastic about the product.”

Leap of faith

At the same time they kept their eyes and ears open to other opportunities in the market. In around 2005 they noticed explosive growth in the American market for phalaenopsis. “The blooms were often inferior quality, but consumers were still prepared to pay for them. We sensed a good business opportunity,” says Overgaag.
They decided to take a leap of faith: in 2006 they started to cultivate phalaenopsis. This also proved to be far from simple at the outset. “It was especially difficult to source good planting stock,” he says. “We originally imported bare root plants from China and then Europe, but they dehydrated too much in transit. We decided to start propagating our own stock. It took a while, but we mastered the art and now phalaenopsis cultivation is the main pillar of our business.”
The company has undergone significant growth in the past five years in particular, with production figures tripling. “To start with, we were just a shade too small for our biggest customers. And the demand for phalaenopsis has mushroomed recently; this variety of orchid keeps on gaining in the popularity stakes in the US and is rapidly becoming a commodity product. We now produce some 2.8 million plants annually and rank among the top three growers in the western US. Our annual production of potted cymbidiums is still 200,000 units too!” explains Overgaag, who acquired the company from his parents in 2009.

Huge range

Today the company operates on a surface of 9 hectares glass, spread over three different sites. One site is dedicated to cymbidium cultivation, one to phalaenopsis propagation and one to cooling and growing on of phalaenopsis. “The plants are propagated in a Venlo model greenhouse, but for growing on and cooling we still use the greenhouse built by my father in 1978 to his own design. Our cultivation system is based on Dutch standards and practice. All the technology and installations in the greenhouses come from the Netherlands; the climate computer, energy saving screens, irrigation systems, internal transport system and so on. We also have a Dutch cultivation adviser and I make an annual trip to the Netherlands to catch up on the latest developments.”
Westerlay grows a staggering 55 different varieties of phalaenopsis and 40 different varieties of cymbidium. “We offer a huge range of colours, but despite that, white is the principal bloom colour with phalaenopsis. The emphasis with cymbidiums is on hues of rust, green and red,” he adds.

Peak moments

The plants mainly find their way to supermarket chains in the western states of the US. “We supply Safeway, Trader Joe’s and Kroger,” Overgaag says. “Orchids have captured a significant share of the American supermarket segment for flowers: you come across phalaenopsis in practically every supermarket these days. We generally supply our orchids in pots, with a label insert and sometimes as part of an arrangement with other plants. Our customers want a frictionless supply process. Meeting their needs is how we provide distinctive added value compared with our competitors.”
The grower does not supply on a contract basis, but regularly sends samples to the headquarters of the retail chains. “The individual branches can then see whether they want to order a certain item or not. Another advantage is that we have our own retail store that sells direct to consumers. That keeps us on trend with what consumers really want.”
The company supplies plants all year round, but there are clear peak moments in demand. Orchids are immensely popular items around Mother’s Day, Valentine’s Day and Easter. “Demand from July to December is generally lower. We grow fewer plants during those months; the greenhouse doesn’t necessarily have to be full to bursting point. There’s no point supplying if there’s no demand. In this respect, my philosophy diverges from growers in the Netherlands – they often want to utilise their production capacity no matter what.”

Attention points

Although Overgaag is satisfied about how things are going, there are points that need attention. According to the grower the point of sale presentation often leaves a lot to be desired. “The phalaenopsis plants are not always presented at their best at the supermarket; the sleeve has been removed, or they are overwatered or underwatered,” he says. “That’s mainly because the staff lack specific product knowledge and often don’t devote enough time and attention to proper care. To make some progress on that point, we ask our sales reps to visit the larger accounts to give tips on plant care.”
Labour conditions are also a continual point of focus. He employs an average of 130 staff; in the greenhouse, the office and the store. “The majority of our workforce in production are Mexican. As a lot of local companies are always trying to recruit staff, we make every effort to keep our employees happy, for example by providing good labour conditions and a realistic salary level. This investment is more than worthwhile; people are glad to work for us. And, don’t forget, motivated staff are willing to go the extra mile.”

The future

Looking forward, one of Overgaag’s objectives is to increase production efficiency. “We do benchmark against Dutch growers and I think we can make significant improvements by refining our production process. As an illustration, we want to boost the percentage of plants with double spikes, now at 70%, to a higher level. Sustainability is also a priority, as buyers are finding green credentials increasingly important. For that reason we are MPS-A certified and are working towards gaining GlobalGAP. We also want to install a solar array in the future to generate electricity.”
The grower is also open to possibly expanding the current product range. “We are constantly alert to market opportunities; a fact we have proven in the past decades. We believe that is what grants you a license to survive. If we encounter an exclusive house plant that offers potential, and complements our current range, we would certainly take it on board.”


In 1978 the Dutch Overgaag family started growing hybrid tea roses in California. In 2002 they switched to potted cymbidiums, which were joined by phalaenopsis in 2005. Phalaenopsis is now their chief product and ranks among the major orchid producing companies in the west of the US. The orchids are supplied direct to supermarkets. Entrepreneur Toine Overgaag’s operational management is focused on process optimisation and sustainability, and he is considering expanding his product range in the future.

Text and images: Ank van Lier.

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Intensive lighting in winter is common in Phalaenopsis growing. A long-running Dutch research project is seeking to answer the question of whether less lighting could be used at that time of year. The trials in the first three years revealed that turning the lights up or down could cut electricity bills by as much as 30% without loss of quality or production. The results from the fourth trial year, with practical trials at Ter Laak Orchids, show that the limit has been reached in terms of quality – at least in the top segment.

The trials run in 2014-2016 by the specialist Dutch research companies Plant Lighting and Plant Dynamics, with support from growers, delivered some surprising insights. One of these was that timing is more important than the light sum in the vegetative and generative phases. They also discovered that a long day of 16 hours produces more CO2 uptake than a day of 11½ hours. Dimming the lights at the beginning and end of the lighting period seems to be possible without loss of production or quality. That generates electricity savings of more than 30%.

Dimming in cooling phase

Based on these results, two follow-on studies were run in the winter of 2016/2017. The first took place in climate chambers equipped with daylight simulators and SON-T lights from Plant Lighting in Bunnik, the Netherlands. In these chambers, the dimming treatment, which can cut electricity usage by up to 30%, was also applied in the cooling phase for the first time. In another room, the plants were lit in line with the biorhythm, starting at 05:00 instead of 01:00. This can save as much as 43% in electricity because it makes better use of free daylight.

Researcher Sander Hogewoning explains: “The CO2 uptake was the same in all three treatments. Yet something caught our eye: CO2 uptake ended relatively late: it didn’t stop until 2½ hours after the lights went on. So the plant rhythm is not always the same, and we have no idea why that is. This indicates that it is important to keep on taking measurements with sensors, otherwise you are taking a risk. We also noticed that the plants were a week behind in the treatments with dimmed light. That can be explained by the fact that the plant temperature was 0.5°C lower on average because the SON-T lamps were used less. In practice, you would compensate for that by turning up the heat. Although the percentage of double spiked plants was just as high, the percentage of branched ones was lower. With these treatments, you’re reaching the limits in terms of quality.”

Practical trials

The limits were explored and found in the second trial as well. This study took place in the Ter Laak Orchids trial greenhouses in Wateringen in the west of the Netherlands, in both the vegetative and cooling stages. The generative stage took place in the production greenhouse. The researchers and growers chose four varieties for the trials: Sacramento, Donau, Jewel and Las Palmas. Martin van Dijk of Ter Laak: “We grow more than 100 varieties here, so we wanted to know what effect a different lighting regime would have on different varieties. The quality and the number of double spikes must remain the same. That’s essential for us.”

In the one 80 m² trial greenhouse, the plants were lit for the usual 16 hours. The plants in the other trial greenhouse were also lit for 16 hours but with the dimming treatment used in the previous trial. The only difference was that the start was delayed until 03:00 in order to make better use of the daylight. To check the quality, the root weight and above-ground weight were measured three times. At the end of the generative stage, the researchers counted the number of double spikes and the number of flowers.

The same or marginally lower

The results? The quality of the plants was the same or marginally lower. With the dimming treatment, the roots in three of the four varieties were lighter than in the control treatment, although the weight of the leaves and flowers was comparable. The number of flower buds was also the same.
Another indicator of quality is the percentage of multiple spikes. With the dimming treatment, only Jewel showed significantly lower results by the end of the generative stage. The percentage was slightly lower in the other two varieties but not to a statistically significant extent. The differences are not massive, but they do show that the limits of dimming were reached in this trial as well.

Hogewoning: “My conclusion after these trials is that dimming saves a lot of electricity and produces the same or slightly lower quality. We advise growers in the top segment not to push the boundaries when looking for savings but to stop a little way from the limit. However, the quality differences are small. Growers with fewer lamps will find that switching the lights on later saves them money. By making better use of free daylight, they will reach their light sum more easily at the time of day that is most important for the plants. And finally, bear in mind that any differences in quality are very much magnified because we are simulating winter for 30 weeks of cultivation. In reality it’s not always December.”

Different choices

With the benefit of hindsight, the growers involved are making various choices depending on the capacity of lamps, but also depending on whether they have a CHP plant or have to buy in electricity, which is expensive. At Ter Laak Orchids they are biding their time. Van Dijk: “With the results of the study and the experience we gained last year, we are waiting to see what the results of next year’s sensor study will be. This winter we plan to turn the lights up and down incrementally, but starting at 01:00 as normal.”

Honselersdijk-based Levoplant has been switching the lights on later since last year. Cultivation manager Erwin van Vliet, a long-standing member of the supervisory committee: “We used to start at 01:00 and we would stop suddenly at 16:00, sometimes even earlier. Now we start at 04:00 in October and finish at 19:00. In November and December we start at 03:00 in order to achieve our light sum. We also turn the lights up and dim them incrementally. That works very well for us because it makes the climate in the greenhouse more uniform. An additional advantage last year was that we had less of an issue with premature spiking. The quality is every bit as good as before.”

Developing knowledge

Are these insights resulting in energy savings? Van Vliet: “We are not saving as much as in the study. We are lighting for longer, although we are saving energy by dimming. Before the study, the trend was heading towards 100% lighting for 16 hours. But we now know that really isn’t necessary. So we need to continue to develop our knowledge – by working together.”

The Pot Orchid Growers Cooperative this year invested in the development of robust, affordable sensors to provide ongoing information on the plants’ light usage. Van Dijk and Ter Laak are certainly convinced of the benefits. “We are installing a wireless network in the new Daylight Greenhouse we are building to allow for the use of wireless sensors in the future.”


The fourth year of the research into lighting Phalaenopsis in winter has confirmed the previous years’ results. The orchid needs a long day, but that can be achieved by gradually turning up and dimming the lights in the vegetative, cooling and generative stages. Switching on the lights later saves more electricity. The quality of the plants in the dimming treatments is the same or marginally lower. The limits of the savings thus seem to have been reached.

Text: Karin van Hoogstraten. Images: LD Photography.

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The LED lamps in the light fittings underneath the top growing layer shine brightly on the plants in the cultivation greenhouse at phalaenopsis growers De Vreede in Bleiswijk in the west of the Netherlands. The light may look white but actually it’s the right combination of colours. It’s one of the innovations that brothers Herman and John de Vreede are working on as part of their drive to supply large volumes of uniform quality orchids more sustainably. They did most of the preliminary research into the right light spectrum themselves.

The phalaenopsis nursery moved to Bleiswijk in 1995. The brothers soon bought the nursery next door and then another two sites 300 metres and 2 kilometres away, making a total of 12.5 hectares of growing space. Each of the sites is equipped for a specific purpose.
The cultivation greenhouse, where the plants spend their first 35 weeks, is heated to a temperature of 28ºC. Then they move to the spike induction site, where they stay until about week 55. Here the plants start off warm and after a few weeks the temperature is reduced to 19ºC to induce flowering. In this phase, the plants are spaced wider apart, staked and sorted by flower size, colour and number of buds. Finally, they are transferred to the finishing site for three to four weeks. Orders are packed and shipped from there.

Large volumes

De Vreede produces 12 million plants per year. Even Herman de Vreede finds it hard to get his head around those numbers. A massive 200,000 young tissue culture plants arrive from various locations every week and leave the nursery again as adult plants more than a year later.
De Vreede specialises in eight outstanding orchids – exclusive varieties with a long life span and offering great value for money. They come from two breeders, with most of their stock supplied by Anthura. “We test about 30 varieties a year, including from other breeders. We want to keep up with the latest innovations.”
The brothers work with large volumes. “We are equipped to fulfil orders of 500,000 units at a time. The biggest challenge for us is getting all the plants to the same stage at the right time. Much of what we do is automated now. Soon we plan to install industrial Fanuc robots which will enable us to respond even more efficiently to market demand.”

Sustainable lighting solution

Orders arrive in peaks. “We supply more than half of our annual production in the first five months of the year,” de Vreede says. “There are a lot of special occasions like Women’s Day and Mother’s Day at that time of year. To accommodate peak production we decided to install a second growing layer above part of the cultivation greenhouse. We now have four hectares of growing space there instead of three. That helps make the crop more sustainable to grow because we’re maximising our space.”
It wasn’t practical to install a second growing layer directly above the original one, either in terms of climate or air circulation. So the brothers decided to put in a second layer along the sides of the three cultivation areas. It is relatively low, just 1.5 metres above the bottom layer. Lighting is needed to make up for the lack of daylight. The standard lighting with SON-T lamps used elsewhere in the nursery can’t be used here.
“There are SON-T lights above this part, but with 600W output, slightly less than the 1000W from the other lamps we use,” Herman de Vreede says. “We went with LED grow lights for the bottom layer. Not only because they generate less heat, but also because they are a sustainable solution. They use less energy and you can choose a particular combination of light colours.”

Three years of tests

At the time there was no such thing as a standard solution. So before they started building in October 2016, they ran tests over a three-year period to see which light spectrum produced the best results. “We tested the effect of different light spectra on properties such as development rate, root development and the hardiness of the plant, both inside and outside the nursery. A lot of knowledge is needed for that, as you have to see what the best result is for each situation. The light spectrum that is most suitable for the vegetative phase of phalaenopsis is not necessarily the right one for the spike induction phase, for example.”
The tests in the nursery were overseen by Simone de Vreede, who had gained a lot of experience in this area and carried out research at her parents’ nursery while still at university. Once they had decided on the light spectrum they wanted, the next step was to find out where to source the lights from. Ultimately they chose Philips GreenPower LED top lighting, which fitted the bill nicely. The lights give out light that looks white. The advantage of this is that it makes it easier to visually inspect the plants being grown in the greenhouse.

More stable climate

“Installing a second growing layer blocked out the daylight from the bottom layer,” says Stefan Hendriks of Philips. “They couldn’t use SON-T because of the short distance between the crop and the lamps: they would generate too much heat. With LED you can create a controllable climate in which phalaenopsis can be grown very efficiently with relatively little light.”
Since the second growing layer was installed in October 2016, the plant specialist has been visiting the nursery every two weeks to carry out analyses and take crop measurements, including length, leaf splitting and dry matter concentrations. In addition, the climate is intensively monitored by means of PAR, temperature and humidity sensors. These observations are linked to the climate data from the computer. “Based on this data, we want to fine-tune the use of the lamps and optimise our cultivation even further. Experience and knowledge are essential when using LEDs. That’s why we carry out a lot of in-depth analyses here,” says Hendriks.


The phalaenopsis grower is also considering buying in LED lights for the other sections when the time comes to replace the SON-T lamps there. Hendriks adds: “Besides being more energy-efficient, LEDs last longer. The life span of the models we use is given as L90. That means that after 25,000 hours of operation, the light output is still 90% of the original level. But the module will still go on working fine after that and will have many burning hours left in it.”
At De Vreede the lamps will probably wear out sooner than that, due to the number of hours they operate. With 14 hours of lighting a day, they are in use for 5,110 hours a year. But that also means that the LED lighting in the new no-daylight situation will pay for itself more quickly.


Dutch phalaenopsis growers De Vreede have 12.5 hectares divided into cultivation, spike induction and finishing sites. In order to have enough growing space available at peak times, they invested in a second growing layer above part of their cultivation area. To light the bottom layer, now in shade, they installed LED lighting with the right light spectrum for the vegetative phase, having first done their own in-situ research into which spectrum to use.

Text and images: Marleen Arkesteijn.

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Next Generation Growing has played a major role in the choices Dutch orchid grower Rob Olsthoorn of OK Plant is making for the new greenhouse he is building in Naaldwijk. “We want to grow in a closed environment as far as possible. The three screens in the greenhouse are helping us achieve that.”

The bottom screen is a transparent, energy-saving fabric. The middle screen is a shading fabric with an open structure which shades 55% of the light. For the top screen, Olsthoorn opted for a light reduction fabric. This screen keeps 99% of the assimilation lighting inside the greenhouse and he can also use it as a blackout when necessary.
The glass is highly diffuse. “This way, I get good light distribution with my triple screen,” the Westland-based orchid grower says, walking through his new greenhouse. “The middle screen shades 50% of the sunlight. That’s plenty. I’m not a fan of screening too heavily. It’s better to have too much light and to have to add in the other two screens than to have too little and not be able to adjust it. It’s important for us to be in complete control so we can create the growing conditions that are best for us. Everything revolves around quality.”

As closed as possible

Olsthoorn grows Phalaenopsis in 9 cm pots on 6 hectares, the last 2.5 hectares of which are currently being built. He has another 2 hectares on which he grows seasonal products like cyclamen, campanula and Primula obconica. “We are targeting the higher segment, such as wholesalers and garden centres. We don’t supply the mass market but specialise in plants with solid added value. And that needs us to be completely focused on quality. Some customers are so strict that they raise the alarm as soon as they see a bad leaf or a mark.”
Next Generation Growing plays a major role in improving quality in Olsthoorn’s greenhouse. “The climate, RH and energy consumption must be as stable as possible so that we can grow in as closed an environment as possible.”
So the nursery opted for a triple screen system which was built into the structure of the greenhouse. You won’t find any end strips made of fabric there. In this part of the nursery, the greenhouse builders Technokas built white steel plates into the greenhouse structure at each end of the screen installations. As a result, the greenhouse is completely energy-efficient and light-proof for its entire service life.


“Sitting down with the right partners in the preliminary phase makes a big difference. This system is actually a screen system 2.0,” says Jeroen de Jonge of Peter Dekker Installaties (PDI). “It saves us a lot of work. Our installers used to only be able to start making the fixed strips once the construction stage was finished. They had to squeeze in around heaters, water pipes and lamps to secure the strips for the three screens to the greenhouse separately. With this new system, the greenhouse builder hangs up the metalwork as the building work gets under way. Then all we need to do is pull up the screen, secure it – and that’s it. This system is much less prone to breakdowns and it’s maintenance-free.”
The grower is also hugely impressed with the system. “I’m ready for the next 20 years now. It’s an investment but it will easily pay for itself in the long term. The closed system keeps the greenhouse climate much more stable and it’s quite a lot easier to maintain. I no longer have any flaps that keep coming loose when I spray down the greenhouse.”

The triple screen they went for in combination with highly diffuse glass also serves a purpose. “It means we can use a transparent energy screen that lets in maximum light. It allows the sunlight in in a much more evenly distributed way.”

More resilient crop

The plants under the screens warm up more slowly, enabling them to absorb more sunlight and therefore more UV radiation, the orchid grower believes. “That produces a stronger plant and therefore a more resilient crop.” He has seen it in Asia with his own eyes. “They grow in plastic greenhouses there. I took my light meter with me and I discovered that they let in a lot more light than we usually do here. And yet the plants were still a rich green colour.”
To prevent the climate from becoming too humid, he is installing a dehumidifier unit in the new greenhouse which blows dry air in from outside. “This means I won’t have to adjust the screens so much and the temperature inside the greenhouse will stay more stable.”

Double top wires

The triple screen has one downside: the screens are very close together. On a 60 cm high truss there are three axles which can rotate independently. If the fabric blows up there is a risk that it can become trapped in the turning axles. “Of course, three screens are always riskier than a single system,” says De Jonge. “So we have installed systems that mitigate that risk. For example, we fitted an axle guard on the axles, like a kind of emergency brake. If there is a malfunction, the motors stop, preventing any consequential damage. Fitting double sets of top wires to prevent the fabric from being blown up is also a must with a triple screen.”
No matter how well the greenhouse is equipped with screens, diffuse glass and a dehumidification system, vents remain a problem. To solve this, Olsthoorn has opted for one-sided ridge ventilation. “Fortunately we were able to build the greenhouse in such a way that the vents could be fitted on the north-eastern side of the roof. If the sun shines at noon and the vents are open, no direct sunlight enters the greenhouse, so the plants don’t get burned.” He is not bothered about the wind. “Ninety percent of the time it comes from the west.”

Outdoor screen

Not only are they building a new greenhouse, they are also adapting the existing one to improve the quality of the crop. The grower also has a triple screen there: an 88% screen fabric, a 66% fabric and a diffuse, transparent screen. “This plus the combination of float glass and 50% chalk screening isn’t enough to further optimise crop quality,” Olsthoorn explains. So fitters are also installing an outdoor screen above the greenhouse roof. The space between the greenhouse roof and the screen can keep the temperature inside the greenhouse around 6-7ºC cooler than outside.
Olsthoorn opted for a 50% screen fabric with an open structure. “That means I don’t need to use forced cooling so much and I need to use less artificial light in dark weather in the summer. That saves a lot of power,” he says.
This may be difficult to justify financially compared with his chalk screening, he admits. “But it will pay off in the long term. The outdoor screen gives us complete control over the weather conditions. If it only helps us deliver fractionally better quality, we will have achieved what we set out to achieve with the outside screen.”


Grower Rob Olsthoorn of OK Plant in the Netherlands deliberately opted for a triple screen for his new greenhouse so as to make it as closed an environment as possible. To improve climate equality even further, he integrated the screen into the greenhouse structure, producing a greenhouse that will be completely energy-efficient and light-proof for its entire service life. The existing greenhouse is being fitted with an outdoor screen which will make the weather conditions completely controllable. The aim of all these measures is to improve quality.

Text and images: Marjolein van Woerkom.

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Greater re-use of drainage water for pot orchids is one step closer with a new compound fertiliser. Phalaenopsis grower De Molenhoek in Bemmel, the Netherlands, has been using this strategy for the past year and a half and it is allowing them to gradually increase the amount of water they recirculate. “We started with the cooling and flowering phases and moved on to the vegetative phase later. We are building up gradually because we don’t want quality to suffer. Our ultimate aim is zero discharge,” Otto Basten explains.

The fact that restrictions on discharges into surface water are becoming ever tighter is old news. Since 2015, emission standards have required pot orchid growers to limit discharges to no more than 200 kg N/ha/year. This will drop to 150 kg/ha/year in 2018 and to almost zero by 2027.
Growers Otto Basten and Marcel Arts are pleased they anticipated future regulations when they built their new facility. Basten: “The floors are in a V-shape with a gutter, so we can collect all the drainage water in four retention basins.”

Centralised facilities

Basten and Arts moved to Bergerden, a greenhouse horticulture area in Lingewaard in the east of the Netherlands, eight years ago. They had run out of options to upgrade their old premises in Horssen, which the partners had taken over from their former employer in 2004. So they relocated to a 1.6 ha site at their present location in 2008, adding a further 1.5 ha in 2011. They grow about 100 species of Phalaenopsis, with 20 main species. The two, three and four spike plants go to florists and retail outlets via direct sales and auctions all year round.
A big advantage of the cluster in Bergerden is that there are centralised facilities there. The CHP plant delivers heat, electricity and CO2. Thanks to the communal rainwater harvesting system, there is always plenty of irrigation water. Basten: “We have two types of ditches: one for clean water and one for wastewater. We collect the water from the greenhouses and it passes along the clean ditches into the central rainwater harvesting system. This has enough capacity for twice the number of horticultural businesses we have here at the moment.”

Adding more depending on EC

So there’s plenty of clean water. And yet the growers are very keen to keep on increasing the amount of water they recirculate. Once they have collected the drainage water in the retention basins, they first treat it with the UV disinfection unit. Then the treated water goes into a separate silo. Depending on the EC, they then mix in water from the clean water silo and new fertilisers.
“We are building up more and more knowledge about watering and recirculation. It wasn’t until we started using these retention basins that we noticed how much water was coming back into them. So we became a lot more aware of how much we were watering. Having started out using a very loose, coarse bark substrate, we later switched to a more compact, finer one that retains the water and the minerals better. That alone reduces the amount of drainage water quite significantly. And because we are using Reci fertiliser, we can keep re-using the water for longer,” Basten explains.


The compound fertiliser Plant-Prod Reci from Horticoop plays an important role in recirculation. The growers have been using this for the past year and a half. Adviser Leo Hoogeveen from the supplier introduced them to it. He explains that this fertiliser was specially developed for orchid cultivation in collaboration with Canadian manufacturers Plant-Prod in 2013. As the name suggests, it is specifically designed to enable targeted recirculation. The adviser explains how it works.
“The purpose of this product is to enable growers to fertilise as cleanly as possible, with minimal ‘background noise’. First of all, it is low in sodium. Many fertilisers contain too much sodium and it accumulates when the water is recirculated. The plant doesn’t absorb it, so more and more sodium ends up in the system. That inhibits plant growth. Removing the sodium enables water to be recirculated for longer.”
Just like sodium, too much sulphate is also a problem when re-using water in plant cultivation. So this fertiliser contains no sulphate but has added magnesium instead.

Stabilised polyphosphate

The fertiliser also boosts plant strength and the root system, Hoogeveen says. “To achieve that, we have replaced most of the phosphates with polyphosphates, which are available to the plant for longer. This has the advantage of strengthening the root system. Also, they are already stabilised, which they wouldn’t be if they were given separately. The pH of separate polyphosphates is too high, so the grower has to acidify the fertiliser himself to neutralise it. Our compound fertiliser works more easily and prevents mistakes. Polyphosphates have the added advantage that they remove inorganic contamination from the system.”
Another feature of the compound fertiliser is that it doesn’t contain a trace of boron, copper or zinc. Many other fertilisers contain low levels of these as standard. “Phalaenopsis growers don’t generally need these elements; they are just dead weight. Levels of boron, copper and zinc are often ‘low’, but in this case it’s ‘no’.”

Correct use

It all sounds good in theory, but how are they finding this fertiliser in practice? Basten is positive, although he immediately adds that every grower will use it differently and that it seems to work better for some species than for others. “The trick is to find out in your own operation how best to use it to increase recirculation. We have stepped up our re-use gradually so as to avoid making mistakes. The percentage in the cooling and flowering phase was already high, but we have always been very cautious in the vegetative phase. That’s the most vulnerable period because the temperature is high and diseases can easily develop. Since we started using the new fertiliser, we have been able to recirculate in this phase too.”

Quality unaffected

So far the strategy has had no negative effects. The quality of the plants is exactly the same as before, Basten says. According to Hoogeveen the fertiliser may even help improve quality, although Basten doesn’t feel he can comment on this. For him, it’s a question of slowly gaining the confidence to increase recirculation.
“You can’t help worrying about spreading diseases via the water. Naturally, we remove any affected plants every week and all the water passes through the UV disinfection unit, but starting off ‘clean’ feels better. That’s why we are doing it in small steps. At the moment we are still discharging twenty per cent of our drainage water.”

Full recirculation

Basten has discovered that he can recirculate more than he first thought. “Everything we need is in the fertiliser in the right proportions. In the past, sodium and zinc levels could easily get too high. Now our drainage water has lower levels of unwanted elements than before. We can see that from the samples.”
Basten thinks full recirculation should be achievable in the future. Of course, a Phalaenopsis grower will need to have the right facilities in place. He also assumes that suppliers’ knowledge levels will continue to develop. “We will be able to do more and more with new products like this and with other substrates too. I’m sure of that.”


Phalaenopsis growers De Molenhoek have been able to increase the amount of water they recirculate by switching to a new compound fertiliser. Because the fertiliser contains very few if any unwanted elements such as boron, copper, zinc and sodium, they can re-use their drainage water for longer.

Text: Karin van Hoogstraten. Image: Gert Janssen (Vidiphoto)

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The ’t Hoog Bos and ’t Nieuw Bos nurseries have jointly developed an innovative watering system together with supplier Van Krimpen: the H2Obloom. This new watering system comprises a transparent vase with a click system on the inside, which provides the plant with water for 10 to 14 days. It is a unique concept, because the vase precisely fits a 12-cm cultivation pot, regardless of the supplier and the type of plant which in the pot.

H2Obloom is highly suitable for the consumer who is unable to water plants regularly, although the transparent vase is also a solution for traders and other growers. Developers 't Hoog Bos and 't Nieuw Bos use the H2Obloom vase with water reservoir to make sure their Phalaenopsis reach consumers in top condition. This idea means that plants always have enough water during the logistics process, and intermediaries do not have to take care of the plants. The innovative H2Obloom water system is available to other growers at Van Krimpen.


H2Obloom is a transparent vase with a click system and water reservoir. The click system on the inside of the H2Obloom vase keeps 12-cm pots securely in place in the vase. An important part of the system is the waterstick, an elongated thin tube, which the user inserts through one of the holes in the cultivation pot. After clicking into place, the waterstick then ends up hanging in the H2Obloom vase water reservoir. The plant can then absorb water via the waterstick, rather like drinking through a straw.

Always enough water

When the reservoir of the water system needs to be refilled, the consumer squeezes the flexible H2Obloom vase, unclicking it from the cultivation pot. The vase can then be filled with water. The system means watering is not required so frequently, and the plant never gets too much or too little water.

H2Obloom introduction

Dozens of customers from the separate nurseries ’t Hoog Bos and ’t Nieuw Bos have already had fun getting acquainted with the H2Obloom. The concept was presented to them with a bottle of Bommels Bitter, to toast the extended life promised by H2Obloom. The H2Obloom will be introduced to the general public during the Royal FloraHolland Trade Fair in Aalsmeer.

Text: Leo Hoekstra. Photo: Pull Position, Jacob Ophof.

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GreenBalanz, of Kudelstaart, is the first Dutch pot plant grower to introduce organically grown phalaenopsis to the market. Although it is still a small number and a modest range, grower Lennard van der Weijden has full confidence in the production and marketing. However, the market still lacks a supply of other organically grown pot plants.

In 2009 Handelskwekerij Van der Weijden was renamed GreenBalanz. This was to underline the sustainable character of the company and allow the owner to better differentiate his company on the market. “We have a greenhouse without gas, we work with natural crop protection products, we use heat pumps and green energy, recirculate our water and do whatever possible to grow as cleanly and responsibly as possible,” he explains. “Our carbon footprint is therefore very modest. In addition, we conduct an active social policy because this is part of our corporate social responsibility.”
Despite all efforts to make the business more sustainable, in 2008 a Swiss customer felt that things should go a step further. “To be able to call ourselves really green the customer felt we should also grow organically,” says the grower. “That meant no chemicals and only organic fertilisers. The buyer wanted us to do this even if it was just in part of the nursery, because then the retail chain Coop – the client in question – could also differentiate itself better.”

Long search

Van der Weijden picked up the gauntlet but soon realised he was going to have invent the wheel himself. Apart from encouraging words, breeders, substrate suppliers and knowledge centres had little to offer that could give him some tailwind. “Apart from biological crop protection, which we were already using, biological cultivation of orchids was completely virgin territory," he says.
The grower did not give up and instead started years of searching for a solution in which plant nutrition stood and still plays a central role. Two factors raised hurdles: the long cultivation period of orchids and the poor growth medium, which is almost completely composed of bark.

Conversion process

“Phalaenopsis is a epiphyte and grows best on bark,” explains the grower. “Bark, however, has hardly any buffer capacity. For standard production that’s not really a problem because in principle all nutrients can be supplied in an available form via the fertiliser. When you apply organic fertilisers, the organic ingredients first have to be converted into inorganic components. That takes a few days and really you don’t have this time. Every time you water, you flush out a large part of the nutrients that after the previous watering were converted into an absorbable form. In addition, bark is a medium with a very poor environment, without any rich soil life that can promote the conversion.”
It took years for the grower to devise the mixture of vegetable and animal manure with which he now achieves acceptable results. He makes the manure into a thin ‘soup’ in a stock container, where the conversion process also starts. Via a separate watering installation – the organic cultivation is strictly separated from the conventional cultivation – this soup is added to the irrigation water.

Slower response, longer cultivation period

The second difficult factor is the long cultivation period. Van der Weijden: “You can try new things and push many different buttons but the results are only visible in the plants five to six months later.”
The limitations imposed by the use of organic fertilisers and the necessity to keep the crop as generative as possible during the hardening off phase does, however, force a steady cultivation regime.
“The quality is no less than that of conventionally grown plants but a completely organic production takes at least three months longer,” says the Dutchman. For that reason he purposefully limits the organic range to the strongest growing varieties. Depending on the progress that is being steadily made the assortment will certainly be expanded.

Quality mark

It is clear that the development of a profitable organic cultivation method requires infinite patience and cannot be carried out on a large scale. In 2014 Van der Weijden eventually reached the point that he was returning reasonable production results that met the official Dutch guidelines (SKAL). “It took a lot of time and energy because initially SKAL did not want us to source material from meristem culture,” he says. “Fortunately, after two years we got the green light, otherwise I’d have thrown in the towel.”

Share my experiences

The first organic phalaenopsis plants were launched on the market early in 2015. In addition to Coop, which loyally stuck to its promises, the grower also supplies other highly-positioned supermarket chains and garden centres in Europe. Although demand is still growing, the share of organic production on the nursery is still less than 10 per cent. It is understandable that it isn’t storming along due to the higher cost- and sales price. However, the market potential is far from fully exploited.
“Over the last 12 months I've spoken to several buyers who would like to sell more organic products than just phalaenopsis,” says the grower. “They find the offer still too narrow and therefore remain reticent.”
When prompted Van der Weijden says that he has not yet been approached by growers who want to copy his initiative. “That surprises me. I am happy to share my experiences with growers who sincerely want to make a start with organic production. Such cooperation can mutually benefit both partners. But it’s logical that I’m not waiting for other phalaenopsis growers to come along. With more of the same we won’t raise the entire organic segment to a higher level.”

Learned a lot

If colleagues join or not, GreenBalanz continues to search for further optimisation. Trials are running with fertilisers, plant improvers and preparations and new varieties are continually being tested.
“We still have a lot to learn,” says the green grower. “What I find very positive is that this project has also yielded a lot for the conventional crop. For the last two years we haven’t had to treat the entire greenhouse for mealybugs, because due to our approach in the organic section we were overall more alert and scouting was more intensive. Previously it was an ‘effort’ that no one looked forward to. Now it is a responsible task with clear added value, which two employees really enjoy doing.”
Another change that has been implemented throughout the nursery is the disinfection of auction containers by placing them in a freezer cell for 24 hours at -20ºC before and after use. The containers are an important contamination source of aphids but the insects can’t survive a temperature of 20 degrees below. “Actually the auction should do that itself, now we do it,” says the grower. “Fortunately it brings us significant savings.”


After years of searching, GreenBalanz, of the Netherlands, has developed a workable method for the organic cultivation of phalaenopsis. Grower Lennard van der Weijden hopes other pot plant crops will follow his initiative. He argues that some retailers find the supply of organic pot plants still too narrow to include in their range.

Text and images: Jan van Staalduinen

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Over the last 30 years, of all the orchid species, phalaenopsis has developed into one of the most popular flowering pot plants. Jan Post, of Dutch market leader Floricultura, has been at the forefront of this development. He predicts renewal within the assortment. People are appreciating plants more, especially those with a natural appearance.

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Phalaenopsis growers sometimes use artificial lighting for 16 hours per day, totalling 8 to 10 mol/m2/day, especially in the winter. For a crop with a cultivation period of 40 to 50 weeks, lighting is therefore a major expense. Measurements show that the correct timing of artificial lighting is more important than the total light sum. Additional research should show whether growers can indeed save around 30% on the lighting hours. Before making such a big change in mindset and operation, growers want absolute certainty.

Since 2012 light specialists Sander Hogewoning and Govert Trouwborst of research centre Plant Lighting, of Bunnik the Netherlands, have been researching the ideal lighting for phalaenopsis. They’ve been doing that with colleagues from Plant Dynamics. It’s rewarding work because very little scientific research has been carried out on this subject. As a result there’s plenty to discover. The Dutch program Kas als Energiebron (Greenhouse as Energy Source) – whose goal is to save energy – was the most important investor in the trials. The crop alliance for pot orchids, of the growers association, LTO Glaskracht Nederland, also contributes and is actively involved in the research.

How much lighting makes sense?

Hogewoning outlines the situation from the beginning. Phalaenopsis is a CAM-plant, just like pineapple, agave and cactus. This means that photosynthesis is different to ordinary C3-plants. CAM-plants are slow growers who only open their stomata in the afternoon. They take up CO2 during the afternoon and night and store it in cells in the form of malate. Storage space is thereby limited. Photosynthesis takes place during the day because light is needed for this. When the malate is all used up photosynthesis for the most part stops.
“Growers now use a lot of light even if the plant isn’t using the light. How much lighting is actually useful for a CAM-plant? And when?” asks the researcher.

Long night unfavourable

In a study in 2014 the researchers showed that a light sum of 6.5 mol/m2/day is enough to fulfil the maximum storage for malate, under the condition that the leaves remain fairly horizontal. More lighting does not yield any more photosynthesis. In addition, the trials showed that allowing in more light during the later phase of cultivation compared with the early phase did not lead to any extra photosynthesis. Another interesting conclusion: Lighting fully in the early morning and afternoon doesn't make sense: During those hours electron transport in the leaves is low.
Trouwborst: “Nevertheless, it is also unwise to provide no light during these inefficient hours. Continuously lighting for 16 hours yielded better results than maintaining a long night and providing 12 hours of light. Growers in practise experience the same. Therefore we wanted to look for the best lighting recipe.”

Step-by-step or low intensity?

This was the focus of the research in 2015. Hogewoning explains his goal. “The aim is to save energy by using less lighting during the hours when the plant hardly uses the light. The question is how far can you dim in the morning and/or the afternoon without loss of production?"
The researchers trialled the variety Sacramento over two sessions. One trial ran from mid March to end May, the second ran from the start of June to the end of July 2015. They started with plants that had already been through the cultivation and cooling phases. They divided them over eight climate units, each of 25 plants. The units simulated daylight similar to that in a winter situation.
Each unit received its own light recipe using SON-T-lighting for about eight weeks. One of these was the control that received lighting similar to that normally used in practise. This was 7 mol/m2/day dosed over 16 hours. Four treatments were dynamic and based on previous research. “For these treatments we maintained a day length of 16 hours. During the inefficient hours in the morning and evening we dimmed the SON-T light to a greater or lesser extent. We switched them on and off in different ways. This saved between 8 and 33 per cent electricity. In addition, two treatments had a day length of 11.5 hours.”

Dimming the light works

The results were very positive. They confirmed the hypothesis that dimming at certain hours is possible and agreed with the results of previous research. The total CO2 uptake for each of the four dynamic treatments was the same as the control treatment of 7 mol/m2/day over 16 hours - even the same as the treatment that saved more than 30% on energy.
Hogewoning: “The savings are substantial; in practise that can amount to hundreds of thousands of euros, not only on electricity costs, but also because growers can replace the bulbs less often.” Trouwborst adds: “Therefore it’s not about achieving the correct light sum but the right timing. You have to use the right light intensity at the right moment.”
Hogewoning points out another important result. “A long night came out the worst, which we also discovered in 2014. When we continuously lit for 11.5 hours, 7 mol/m2/day, the CO2-uptake by the plant is less than in the dimming treatment with a 16 hour day length and a light sum of 5.2 mol/m2/day.”

Questions from commercial growers

These are spectacular results, but will phalaenopsis growers dare to dim the SON-T-lights early in the morning and afternoon? Trouwborst: “We recently presented these results to the supervisory commission and the crop alliance for pot orchids. Their first question was: ‘Does anyone do this in practise already?’ With millions of euros of plant material at stake growers won’t so easily alter their lighting methods. That’s why it is important to slowly scale up this research. The crop alliance is following this very closely.”
Growers, of course, want to know if a good uptake of CO2 translates into plant quality and number of buds. The researchers have also measured that but Hogewoning points out: “The number of plants was too small to draw conclusions. However we do see that the number of flowers is in line with the CO2-uptake. The treatment with the least uptake – a long night, 5.2 mol/m2/day – clearly led to fewer flowers.”

Repeat trial

Because they want to see these positive results confirmed on a larger scale, the researchers are running a repeat trial with more plants. For this they invested in new climate units of over 2 m2, in addition to their existing smaller units. “In these new units we can even let the sun slowly rise and set. All year around we can mimic the light situation in the winter, without being dependent on the weather conditions,” explains Hogewoning.
The trial was due to run until the end of May 2016. In consultation with the growers the researchers ran the two most successful treatments as well as the control treatment, which is similar to that currently used in practise. Hogewoning: “The crop alliance is very curious about the results. They are waiting with baited breath. In the meantime growers who have questions can discuss it within the group.”


Commercial phalaenopsis growers use a lot of artificial lighting. Research indicates that the timing of the lighting is more important than the total light sum. It seems that growers can dim the lighting early in the morning and in the afternoon without any negative effects. If these initial results are confirmed it appears that at least 30% can be saved on electricity.

Text: Karin van Hoogstraten. Images: Gert Janssen (Vidiphoto)

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We’ve almost reached the end of our first year at our phalaenopsis young plant location in Brazil. Until now growers bought material from laboratories because importing cuttings with soil is not allowed. Therefore they had to propagate their own young laboratory plants. More and more growers want to stop this because it is a specialised job. Therefore, we as Sion, decided to try to do that for our clients at a specially equipped location.

Even within one year many changes have occurred. Brazil landed in a crisis and it has become normal to import cuttings in glued plugs from the Netherlands. The crisis has made everyone incredibly careful about making investments and the costs of energy and imports have skyrocketed. Horticulture seems to be riding it all reasonably well. Luckily people still buy a bunch of flowers or a plant. Good quality still gets a very good price but poor quality doesn’t stand a chance. Growers believe that a minimum of 40% of the population has money over for flowers or plants. However, in terms of logistics this group is still insufficient. It still costs the necessary time and money.
From the strong growth in our orders we notice that growers increasingly value the Dutch varieties, planning and quality instead of the cheaper types, mostly from Asian countries.

Because it is now possible to import plugs with cuttings it puts more pressure on us to perform better locally. That is not a problem until the Brazilian summer strikes. A summer with temperatures sometimes up to 40ºC, long-lasting rainfall and humidity often above 90% is another ball game. It seems that many growers have difficulty steering their crops through this. Cutting back on expensive energy is also asking for problems.

Despite the fact that we don’t economise on that and we have a lovely high greenhouse we still have to take extra measures (especially cooling) to counteract it. But we’ll still need a few lessons in the Brazilian climate to come completely faultlessly through the hot summer. Of course we are in a position that we can supplement any shortages with cuttings from the Netherlands. But if everything was so easy then everyone would continue to do it for themselves, wouldn’t they?

Eric Moor, phalaenopsis breeder