Is it worth it to add microbes and mycorrhizae to our soil

Q: We are organizing a community garden. Is it worth it to add to our soil a product that has microbes and mycorrhizae? 

A: Products like this are heavily advertised. They promise great results using beautiful photos. But my mission as a gardening educator is to stick with the science that investigates the claims of garden products. Researchers at Washington State University tested products that touted microbes and mycorrhizae. Their research was reviewed by their peers in other parts of the country. Their summary concluded that adding mycorrhizae to gardens is “…generally ineffective and unnecessary….”. Your garden will be inoculated with mycorrhizae naturally from falling leaves, compost, and wood chip mulch. Avoid rototilling the beds after the first growing season. Tilling harms the mycorrhizal environment.

Many gardeners fervently believe in adding microbes and mycorrhizae to soil. It’s a free country and you can spend your money on whatever you like but you won’t find mycorrhizae additives in my garden shed.

Garden Myths

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