Many thanks to Ben for his excellent talk about mulches. While his research concerns hydromulch, a very promising, earth-friendly mulch for potential use in commercial operations, he also shared some excellent information about mulches that the home gardener can use. Some interesting topics discussed include:
• If you are building a garden bed from scratch, consider using the Hügelkultur method (which uses a great deal of mulch). Start with large branches, top with soil, then layer with smaller and smaller compostable plant materials. The gradual decay of this biomass will be a consistent source of long-term nutrients. There are many articles about Hügelkultur available on the Web–here is just one: https://www.permaculture.co.uk/articles/the-many-benefits-of-hugelkultur/
• Ben’s favourite mulch is cacao hulls. When spread, it grows a fungal mat between the hulls that most weeds can’t penetrate. As well, its smells like chocolate when it rains! If anyone knows of a local source for cacao hulls, we would appreciate your input so we can share with our members.
• Don’t create a mulch volcano around a tree trunk (when mulch is placed around and up the base of a tree trunk covering the bark and root flare). This will eventually kill your tree by permanently shading and keeping the base of the tree in constant contact with moisture allowing for rot, bacterial and fungal infections. It can also cause root girdling that could cut into the tree cambium layer—which, if severed around the trunk circumference, will eventually kill your tree. Follow the ‘3-3-3 Rule’: Spread a 3-inch layer of mulch in a 3-foot donut around the tree making sure to leave at least 3-inches between the mulch and tree stem.
We wish Ben much success in his further study of this important subject of organic hydromulch. Ben’s presentation can be viewed here: