Trials with peat-free substrate turn out surprisingly well |
|
|
|
|
 |
| 253 sec |
'Despite Acer's sensitive roots, hardly any difference noticed'
The innovation circle Weerbaarheid in de Praktijk Zundert (LTO Trees, Perennials and Summer Flowers) set up five practical trials with peat-free substrate last year. This was done in cooperation with BCT Treeport, Varta Valorisatielab, GroeiBalans and substrate producers. Patrick Braspenning of Nursery J. Bevers & Zn and substrate producer Legro were also involved. "Our main product, Acer, is a crop with sensitive roots," says the grower. "Still, I saw no difference in the result and did not have to adjust my working method. In May, we will repeat the trial to gain more experience."
| Grower Patrick Braspenning will continue the trial this spring. |
Patrick Braspenning did not hesitate when asked to participate in the trials. "We supply a lot to the UK market, which is known for its critical attitude towards peat," says the grower from Wernhout. "You read about it in all the magazines, but so far, not a single customer has asked us to switch to peat-free substrate. For now, I prefer to stick to my trusted peat mix. I know exactly how to work with it, and even plants with sensitive roots, like Acer, thrive in peat."
Opportunity to gain experience
The tree grower is aware, however, that at some point he will need to switch to a substrate consisting mainly of renewable raw materials, such as coco and wood fiber. If his British customers do not demand it, the necessity will come from the Dutch substrate agreement. The terms set out in that agreement provide for a gradual increase in the use of renewable raw materials with a low environmental footprint. "It's just a matter of time. We will have to take that step eventually, and it's easier when you've done your homework," Braspenning continues. "Taking part in this project seemed like a great opportunity."
Renewable raw materials
For producer Legro from Helmond, the project was an opportunity to let its loyal customer gain experience with sustainable substrate, which the company has been familiar with for years. "Traditionally, we are associated with peat, but we've also been using renewable raw materials like coco and wood fiber for a long time," says substrate advisor Tim Heestermans. "Legro was one of the first companies to import coco fiber on a large scale and has its own production sites in India and Sri Lanka. There, too, we pay a lot of attention to sustainability and quality assurance. Many of our customers, including in tree nurseries, have switched in recent years to blends with less peat and a greater share of renewable materials. That works fine, as long as the grower is aware of the specific characteristics and differences compared to 100 percent peat. These differences always exist to some degree, but they should not be an obstacle to change. We are pleased that Nursery J. Bevers was willing to participate in the project. The trials were supervised by Varta and GroeiBalans, which also gives growers confidence."
No wet feet
Braspenning and his team grow garden plants in container sizes ranging from C4 to C90. Acer, Hamamelis, Magnolia and Syringa are the main varieties. As the grower mentioned, Acer in particular is very demanding when it comes to substrate. "Japanese maples don't like wet feet," he explains. "If the bottom of the pot stays wet and cold for too long, it will result in slower growth, root death and soil-related diseases. The substrate must contain enough air and be able to retain water. So good drainage is always essential."
For the trial, Legro composed a substrate from renewable raw materials coco and wood fiber, supplemented with perlite. From spring onwards, this was tested alongside the trusted peat mixture. The base fertilization was adjusted to the needs of the plants and the characteristics of both mixtures, such as pH and buffering capacity for water and nutrients.
Tim Heestermans: "Peat has excellent buffering properties and is very stable. With the alternative blend, we try to come as close as possible to those qualities while maintaining high, consistent quality. That is essential for longer cultivation cycles. In general, fully peat-free substrate tends to have a slightly drier character than pure peat. Watering and fertilization should be adapted accordingly. During the trials at Bevers, this was hardly necessary due to frequent rainfall."
Expectations exceeded
Braspenning confirms that the trial results exceeded his expectations. "I was pleasantly surprised. Previously, I had run a small trial with a substrate containing different materials, not involving Legro, and the plants didn't respond well. With Legro, Varta and GroeiBalans involved, I had more confidence. You often hear that major cultivation adjustments are needed when switching to peat-free substrate, but due to the abundant rainfall, these were hardly necessary. In the peat-free blend, root development during the initial growth phase was even slightly faster and the plants developed more fine roots, which I like to see. These are essential for growth. Above ground, no differences were noticeable. As far as I'm concerned, the blend passed with flying colors."
A visual assessment took place on 5 June (left) and 9 August (center), among others. The containers with blue labels contained peat; purple indicated the alternative substrate. At the bottom of the root ball, it is clearly visible that the alternative substrate drains well.
Continuing the trial
The grower notes that 2024 was a relatively wet, lush growing year. "If the circular mix had a drier character, that didn't really show due to the weather. On the other hand, we now know that drainage is not an issue. Our Acers grew just fine on it. I expect we can make the step to sustainable substrate with this blend, but I'm not switching over completely just yet. In May, we'll repeat the trial using both substrates. If we get a dry, warm summer, any differences will probably become more apparent. I actually hope so, because then I'll be able to experience how to deal with that. Legro, Varta and GroeiBalans will remain involved. I'm curious to see how it goes."
Heestermans is also looking forward to it. "We're happy to share our knowledge and experience with customers, but the grower is the one in control. Potting method, frequency and method of watering, and the fertilizers used all influence the physical, chemical and biological properties of the substrate. Anyone who takes the time to get to know a new blend properly—preferably in a separately controllable area like a test plot—will have little trouble getting the best results from it. Even in variable weather conditions. It's also important to regularly evaluate things with your crop advisor and substrate specialist."
René van Gastel: 'Look at the analyses and act accordingly'
The trials with circular substrate are technically supervised by crop advisor René van Gastel of GroeiBalans. "Together with Varta, we visited the trials monthly and conducted visual assessments, including underground. Varta also collected samples for analysis. The Legro mix definitely performed well. The main raw material is coco, which is already widely used in tree and perennial cultivation. Perlite is also a well-known component, mainly contributing to drainage and a good air-water balance in the containers."
|
The analyses sometimes revealed small differences. "If you are aware of those and act accordingly, it's no problem at all," says Van Gastel, who ends with an important message: "Realize that each blend behaves differently and requires adjustments in cultivation. Those who were used to growing with peat on autopilot will have to turn that off and keep a close eye on things. That means: more measuring, closely reviewing analyses and doing what's necessary to keep the root environment in top condition."
This article was previously published on 18 April 2025 on the Boom In Business website.
| Boomkwekerij J. Bevers en... | |
| |
| LOG IN
with your email address to respond.
|
|
|
| There are no comments yet. |
Tip the editors
|
