Hattie Moore, garden apprentice
If you’re a gardener you may have seen white, threadlike veins twisting through organic matter and rich soil, they look too thin to be plant roots yet are clearly part of the root environment. Have you ever stopped to wonder about them? Recently I learned that they are in fact mycorrhizal fungi and they are in a mutualistic relationship with your garden plants.
These fungi are unable to photosynthesise and cannot create their own food, so they depends on the food created by plants. Their white, threadlike root system (hyphae) extend into the soil around the plant and cover an enormous surface area, hundreds of times larger than the surface area of the plant’s own roots.
Two types of mycorrhizae are found in soil: Ectomycorrhiza creates a sheath of fungus on the outside of tree roots and interacts with the surface cells; alternatively Endomycorrhiza sends fungal strands called hyphae directly into living root cells. Both types take stored carbohydrates from plants roots and in return provide water and hard to absorb nutrients to root cells.
Mycorrhizae are natural networkers, linking neighbouring plants together via the roots and transfer nutrients to plants with a greater need. This symbiotic relationship has existed for millions of years, yet has only relatively recently been accepted as a key factor in the health of plants. The extended surface area of the mycorrhizae helps the uptake of water, and so increases the plant’s tolerance for drought conditions. Their presence in the root systems also prevents pathogens and pests, such as nematodes, from attacking.
Here at Fulham Palace we have begun introducing mycorrhizal fungi in the form of dusty granules into the soil when planting, sprinkling it into the hole dug for the new plants, especially for bare root plants, shrubs and trees.
Naturally occurring fungi are less present in cultivated soil. Garden practices such as using fungicides, digging and using fertilisers damage the naturally occurring fungi. We use mycorrhizae in combination with other practices that prevent damage to the soil environment and the microorganisms within it. We are organic within our walled garden (never using herbicides and pesticides), and instead of fertilising or liming the soil, we mulch once a year. We operate the ‘no dig’ system within the vegetable patch which means we do not damage the structure of the soil or the microorganisms within it.
The proof of our healthy soil organisms can be seen (and tasted!) on our market barrow, which soon will be laden with fruits and veg grown in our walled garden.
If this article has piqued your interest in mycorrhizal fungi you can find out more in this article by Dr Linda Chalker-Scott or on the RHS’s website.