Brian Jervis Ask a master gardener
“I’ve been hearing a lot about a fungus called mycorrhizae that everyone seems to think I need to add to my garden soil. What is it and do I need it?” — CG
Mycorrhizae can play a very important role in plant health, but because they are invisible, their importance is often overlooked.
Mycorrhiza means “mushroom root,” and these fungal roots have mutually beneficial relationships with the roots of many plants. Because of this mutually beneficial relationship, mycorrhizae cannot survive for long in the absence of a host plant. This relationship has no disadvantages, only advantages.
There are two basic classes of mycorrhizae: ectomycorrhizae and endomychorrhizae. Ectomycorrhizae grow at the ends of young roots and invade only the outer cell walls of the root. On the other hand, endomycorrhizas invade the roots of the plant and exist entirely within the plant.
Mycorrhizal fungi are considered beneficial for 80 to 90 percent of all plant species. Plants not included in this group include azalea, beet, blueberry, broccoli, Brussels sprouts, cabbage/kale, clove, cauliflower, cabbage, cranberry, heather, blueberry, mustard, protea, rhododendron, sedge, and spinach.
People also read…
Since the fungus cannot produce its own carbohydrates, it extracts carbohydrates from the host plant. In return, the mycorrhiza absorbs nutrients from the soil to pass them on to the plant.
The branching elements of the fungus are known as hyphae, and these hyphae are thinner than the roots of the plant. They average 1/60th the diameter of smaller plant roots. Because of their small size, they are able to penetrate the soil in ways that the plant’s roots cannot reach, increasing the plant’s ability to absorb nutrients. The main benefit that mycorrhizal fungi offer is access to a greater amount of water and nutrients such as nitrogen, phosphorus, zinc, manganese and copper.
Other reported benefits of having healthy mycorrhizae in your garden soil include increased drought and salt stress tolerance, greater transplant success, higher crop yield with improved flowering, increased water and nutrient uptake, and improved soil structure.
Mycorrhizae are available as a soil amendment for a variety of situations including vineyards/orchards, nurseries, commercial growers, landscape or home gardens. One thing to note is that mycorrhizal fungi are naturally occurring in most soils, so it’s not always necessary to purchase them as a soil supplement. However, if you’ve run a soil test with results that suggest your nutrient levels are adequate, but you’re still having symptoms of poor nutrient levels, it might be a good idea to add some mycorrhizae to see if the problem goes away fixes itself.
Mycorrhizal fungi are available as granules, powder or in a liquid solution. Typically you will find them listed as ingredients in organic fertilizers. Much luck!
You can get answers to all of your gardening questions by calling the Tulsa Master Gardeners Help Line at 918-746-3701, stopping by our Diagnostic Center at 4116 E. 15th St., or emailing us at firstname.lastname@example.org.
Tulsa World Scene Podcast: Tributes to Woody Guthrie and Bass Reeves