Gardening season is in full swing, and resourceful gardeners are always on the lookout for helpful tips. Here's one that we heard through the grapevine: using mycorrhizal fungi in your garden will reduce its watering needs, and also increases your plants' nutrient uptake, resulting in healthier plants.
Mycorrhiza ("myco" is Greek for mushroom, and "rhiza" for root) refers to the symbiotic association between certain kinds of fungi and the roots of plants -- literally, it's "root fungus." In this mutualistic relationship, the fungi will colonize plant roots and spread out a microscopic network of filaments underground called "hyphae," thus allowing the plants to soak up more water and nutrients, while taking sugars in exchange. On its own, this network of fungal hyphae is called a “mycelium” -- which we know has amazing properties, prompting mycologists like Paul Stamets to call mycelium "Earth's natural internet."
But back to the mycorrhiza, this fascinating symbiosis between fungus and plant. Wildlife biologist Douglas H. Chadwick explains on Mother Earth News the finer points of how this mutually beneficial relationship works:
Ten to 20 percent of the sugars a plant produces through photosynthesis are absorbed by the mycorrhizae. In return, the fungus delivers many essential nutrients to the plant and increases drought resistance. Higher crop yields can be the result for gardeners. As the ends of the hyphae weave among soil particles via cracks and crannies too small for even the narrowest root hair, the mycelium becomes an auxiliary root system that’s in contact with a subterranean volume of soil from several hundred to 2,500 times greater than what the plant could reach alone.
While it's estimated that 95 percent of plants benefit from some form of mycorrhizal relationship. Most notably however, plants in the mustard family (broccoli, Brussels sprouts, cauliflower, collard greens, kale and radishes), beets and spinach do not appear to benefit from mycorrhizal fungi.
In this interview, professor Roger Koide of Brigham Young University explains a bit more in detail about the various kinds of mycorrhizal fungi, and his view on some of the commercial products that are available (though you can certainly create your own mycorrhiza at home).
So in the interest of healthier plants, it makes sense to encourage this partnership. Chadwick recommends keeping soil tilling to a minimum, keeping live plants in your garden beds, even in winter (mycorrhizal fungi need live plants to survive), avoiding pesticides, fungicides, and chemical fertilizers, and avoid applying too much phosphorus, which can discourage mycorrhiza. Read more over at Mother Earth News.