Beneficial fungi Gardening

Learn How Mycorrhizal Fungi Benefits Your Trees and Shrubs

Photo: smileus, depositphotos

Owning a healthy and flourishing organic garden is nothing short of a delight. But maintaining a garden needs a lot more than just sunlight, water, and soil. Are you aware of the dynamic network of microorganisms at work behind your thriving plants and trees? These organisms remain in the soil and help in the growth of your trees and shrubs. They decompose organic matter to enhance the overall fertility of the soil. Mycorrhizal fungi belong to this group of helpful microorganisms. But how do these fungi benefit your trees and shrubs? Let’s take a look. 

What Are Mycorrhizal Fungi?

Mycorrhizal fungi act as an extension of the host tree’s root system. Photo: Premier Tech

Mycorrhizal fungi or mycorrhizae are beneficial fungi that colonize the roots of trees and plants for their survival. The term mycorrhiza means fungus roots. These fungi can’t survive without remaining connected to roots. In exchange, they provide several benefits to the host plant or tree. In other words, these fungi form a symbiotic relationship with their host. More than 90% of species of trees and plants existing in the world form beneficial associations with mycorrhizal fungi.

Benefits Provided by Mycorrhizal Fungi for Your Trees and Shrubs

Mycorrhizal fungi indulge in several mutually beneficial exchanges with the roots of the host tree or plant. Some of the major benefits offered by mycorrhizal fungi are as follows:

Tree root system.
Photo: Flash Alexander,
  • Provide Accessibility to Water and Nutrients in Difficult-to-Access Places

    Mycorrhizal fungi help roots find water and nutrients in places where accessing them may not be easy. The fungi serve as an extension of the host tree’s root system. They can enhance the absorptive surface area of the roots by as much as 700 times! This makes it easy for trees to stretch deep within the soil to places where the roots can’t reach and absorb essential resources, such as water and nutrients. Such a network proves to be exceptionally beneficial for a tree during dry spells when water becomes scarce.
  • Increase the Bioavailability of Nutrients and Fertility of Soil

    Mycorrhizal fungi enrich the soil with enzymes that play an active role in unlocking and dissolving essential nutrients within it. Due to such a reaction, the bioavailability of nutrients increases, making it easy for plants to absorb and utilize them. These nutrients include calcium, phosphorus, magnesium, copper, iron, zinc, etc. Further, mycorrhizal fungi also capture and store excess nutrients from the soil through its intricate network. These nutrients are stored for later use, so the fertility of the soil increases.
  • Protect Trees and Shrubs and Increase Disease Resistance

    The soil is the breeding ground of not just beneficial fungi, but harmful fungi too. Some varieties of harmful fungi can be so destructive that they can even kill a tree. Once this happens, you may be left with no option other than to use a hand saw for trees to cut it down.

    Mycorrhizal fungi help to protect trees and plants by forming a protective web around the roots. This web limits harmful fungi, diseases, and certain varieties of harmful bacteria from accessing the roots. The web also prevents pests from harming your trees. For instance, mycorrhizal fungi forming colonies on the roots of plants serve as a deterrent for attacks by root-chewing insects and parasitic root-knot nematodes.
  • Enhance Resilience to Environmental Changes and Other Stressful Conditions

    When a tree can access water and nutrients from deep within the soil due to the intricate network of mycorrhizal fungi, it increases the tree’s ability to survive in adverse circumstances. For instance, if the tree faces drought conditions, it won’t die due to the lack of nutrients and water. Rather, it equips itself to withstand the heat, stress, and other environmental changes even as it draws the necessary nourishment from deep within the soil with the help of mycorrhizal fungi.

How to Ensure Ideal Soil Conditions for Mycorrhizal Fungi to Thrive?

It wouldn’t be wrong to say that mycorrhizal fungi are among the best friends your garden can have. Here are a few ways to create optimal soil conditions for the fungi to flourish:

Small shovel and potting soil.
Photo: Neslihan Gunaydin,
  • Always use organic fertilizers. Ensure that your fertilizers have no phosphorus and less than 5% nitrogen. Note that phosphorus can cause damage to mycorrhizal fungi. So, stay away from using concentrated NPK fertilizers.
  • Avoid spreading broad-spectrum fungicides, herbicides, and pesticides in your garden. While some varieties of these products are safe to use, many can kill off mycorrhizal fungi and deplete your garden soil.
  • Prevent spraying for mosquitoes in your garden as such sprays settle into the soil and kill beneficial varieties of fungi.
  • Stay away from tilling or compacting your soil. When you indulge in compacting soil, you run the risk of crushing the delicate fungal tubes. Tilling can result in the tearing apart of the fungi’s fibrous networks.

In Conclusion

When it comes to your trees and shrubs’ healthy growth and nourishment, mycorrhizal fungi go a long way to ensure the same. They form an essential part of the soil ecosystem. Now that you know all about them, go ahead and take advantage of this beneficial microorganism for your trees and plants.

Garden writer and blogger, author of 65 gardening books, lecturer and communicator, the Laidback Gardener, Larry Hodgson, passed away in October 2022. Known for his great generosity, his thoroughness and his sense of humor, he reached several generations of amateur and professional gardeners over his 40-year career. Thanks to his son, Mathieu Hodgson, and a team of contributors, will continue its mission of demystifying gardening and making it more accessible to all.

5 comments on “Learn How Mycorrhizal Fungi Benefits Your Trees and Shrubs

  1. I use an organic starter fertilizer with Mycorrhizal fungi in it every time I put in a new plant. I mix it into the planting hole. After that I switch to adding a ring of compost around the plant once or twice a year. Is that enough to keep the fungi nourished?

  2. There’s a film on netflix just now – Fantastic Fungi…I would totally recommend watching this. This article is so interesting, and the film takes this two or three steps further. It’s definitely on the same par as My Octopus Teacher…??

  3. Paul Pietsch

    Are all the microhiza that are available in garden centers the same

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