What’s so attractive about that stuff? Can’t we switch to peat-free potting soil? Potting soil is ‘essential’ for the ‘healthy development of plants’, according to the website potgrond.nl. Peat or peat in potting soil has the most important characteristic that it is airy, says the seller of the webshop on the phone. “It is good for the root growth of plants. It also absorbs a lot of water.”
Another important property: peat contains very little, say experts. And that’s nice. For example, it does not contain seeds of other (un)herbs that can germinate.
Contains no food
“Peat and peat are actually a dead product,” says Mathijs van Houtum. He has an organic nursery and makes organic potting soil, garden soil and compost, which are sold under the name Bio-Kultura. “Peat retains moisture well, but it contains no nutrients.”
So peat does not contain the nutrients that plants need to grow – nitrogen, phosphate and potassium. You add it, exactly in the amount that plants need. As a grower, you have everything under control. It is also ideal that you know fairly precisely what the acidity of peat is. This can vary with potting soil based on compost.
Remarkably enough, Van Houtum also uses soil from peat areas in its organic nursery. Not peat, but the top layer of raised bog: peat moss. “We use pots of 9 by 9 centimetres. It is quite difficult to keep things airy and moist in them. With peat moss we can do that. The plants we grow grow most beautifully in them, the potting soil lasts up to 15 years Incidentally, our use of potting soil is minimal when I see how many plants we produce from it.”
Sometimes ‘worthless mixtures’
Yes, he really wants to get rid of it, he says, but: “I have done 1001 tests with peat-free potting soil, sometimes there are worthless mixtures in between. Then you have a peat-free product, and your plant dies. Well, then everyone throws it away.”
The seller of potgrond.nl also says: “Now we think extracting peat is a major intervention in nature, but we cannot go completely peat-free. Then I have to fire three people. Then the exercise is over. As long as the market doesn’t have enough alternatives. Just can’t.”
Can we get around peat?
No alternatives? So we can’t get around the peat? Well, it is possible. Only: these alternatives have disadvantages. Peat can be replaced by coconut fibre, a residual product from coconut plantations. Coconut fiber also retains water very well. “But that comes from India and is transported by seagoing vessels, which is also undesirable,” says the man behind potgrond.nl.
“Coconut is now seen as the holy grail,” says grower Van Houtum: “It’s a very nice replacement. It’s light and airy and plants grow reasonably well in it. Only: it comes a long way. And we forget that there are whole jungles are cut down for those plantations. A lot of fertilizer and poison are used during cultivation. And the coconut fiber has to be washed, that polluted water runs into the wild. And then it still has to be transported to the Netherlands.” The road to sustainability is ‘a very difficult one’, says the grower.