Notes from the garden shed: our love for mycorrhizal fungi

As Emma, our garden intern, and I work alongside Paul Richens, Global Generation’s Garden Manager, we are often reminded of one of his favourite sayings…“Feed the soil not the plant”, writes Community Gardener Ciara Wilkinson.

We grow our fruit and veg organically at the Skip Garden - no pesticides, no fertilisers, no scary chemicals that make your plants ’bigger’ or ‘greener’. Instead we process our kitchen and garden waste into rich compost, harvest ‘worm tea’ from our wormeries and grow comfrey (variety: Boking 14) that is concentrated into a thick liquid fertiliser. When added to our soils those tinctures and potions work positively with the microbes, bacteria and fungi that live below the surface of the soil. 

This subterranean world is home to Mycorrhizal fungi and on Tuesday we were lucky enough to have been invited to PlantWorks in Sittingbourne, where this friendly little fungus is grown, packaged and shipped out in the form of RootGrow (an organic mycorrhizal ‘top-up’ for your soils). 

So you may ask…

What is mycorrhizal fungi?

For at least 500 million years, the organisms known as mycorrhiazl fungi have been colonising the planet, providing a secondary root system for plants. 

When we learn about plant anatomy in school, we are taught that there is as much of the plant below the ground as there is above it. However, when we consider that mycorrhizal fungi can increase a plant’s underground surface area by up to 700 times then we must rethink this assumption.

Underground surface of plant increased by 700 x

Underground surface of plant increased by 700 x

And, you may wonder…

Why is it so important? 

Mycorrhizal fungi have a unique relationship with the plants they interact with. Increasing the surface area of the plant root system by up for 700 times brings many benefits to the plant. 

The four main roles of mycorrhizal fungi for the host:

  • Improving nutrient uptake, including phosphorous, nitrogen and zinc
  • Protection from biotic stress, such as pathogens and herbivores
  • Protection from abiotic stress, such as drought and heavy metal tolerance
  • Soil stabilisation through the production of glomalin (a sticky glycloprotein). Through binding the soil together, glomalin prevents damage from natural processes like erosion 

For all of these benefits, the plants provide carbon to their mycorrhizal that are formed through photosynthesis. 

We use RootGrow regularly when planting our fruiting trees and bushes. However, a growing number of scientific studies are suggesting that all but a couple of plant families (the Cabbage or Brassica family, for example) depend on this mycorrhizal relationship for their improved survival. 

So here are a couple of our…

Growing tips 

Use RootGrow with every new planting! There are different species available that suit various plants. 

Leave the roots of dead plants in the soil, the spores from mycorrhizal will be left in the soil ready to help out your next plants. But make sure the plot isn’t left bare for too long. Top-up your soils with microbial and bacterial life too by watering with a dilute of ‘worm tea’ and water before you plant this Spring!

Test on clover ... see how healthy the plants are with Rootgrow!

Test on clover ... see how healthy the plants are with Rootgrow!