Growing with Less Impact: Sustainable Alternatives for Peat and Rock Wool in Horticulture
Monday 24 March 2025
In horticulture, everything revolves around growth. To enable this growth, we often rely on materials that burden the environment, such as peat and rock wool. It鈥檚 time for innovation. Fortunately, more and more smart, sustainable solutions are emerging.
Peat retains water well, making it popular in potting soil. However, it is extracted from vulnerable peat bogs, which naturally store CO鈧�. Once peat is extracted, a large amount of CO鈧� is released. Rock wool, on the other hand, is not biodegradable and contributes to waste. It works well for plant growth but leaves a lasting footprint.
Biochar: A Smart, Local Alternative
Researchers at the Foundation for Innovation in Greenhouse Horticulture (SIGN) have been searching for more sustainable alternatives to peat. One promising option is biochar, a form of charcoal produced from biomass that can be made locally. Biochar retains water just as well as peat but without CO鈧� emissions. Bonus: it improves soil structure and contributes to carbon storage.
Circular Fibers: Waste Streams Turned into Growth Power
What if waste suddenly had value? SIGN experimented with fibers from local waste streams, such as pruned branches or plant leftovers. The results? Slightly slower growth at first, but then strong performance. And all this with a much smaller ecological footprint compared to traditional substrates.
Smart Layers: Stratified Substrate
Another smart innovation: stratified substrate. This method involves building up the pot in layers鈥攃oarse at the bottom and fine at the top. Why? It ensures better water distribution and prevents the bottom layer from staying too wet. Tests showed that these substrates performed just as well, if not better, than traditional mixes. More efficient water usage, without compromises.
Organic + Microlife = A Powerful Combination
What happens when you combine organic substrates (like wood fiber or recycled fibers) with micro-life such as compost extract? A lot of good, according to research. Plants grew just as well as on rock wool 鈥� sometimes even better. And you鈥檙e also working on a healthier soil.
The Future: Dissolvable Glass Fibers
An innovation that sounds like science fiction: dissolvable mineral glass fibers. They serve as both a growing medium and a fertilizer, completely dissolving in water. No waste, but efficient nutrient uptake. If this technology takes off, it could be a game-changer for the sector.
What Does This Mean for You?
Horticulture stands at a crossroads. By opting for alternatives, from biochar to circular fibers, you reduce your ecological footprint. At the same time, you contribute to healthy crops and future-proof production. Sustainable substrates are not a compromise. They are an opportunity. For you, for your business, and for the planet.
