A garden bed with a persons hands tending to the tiny seedlings, there is beneficial fungi for plants inside the soil

The frost is setting in and days are getting shorter - it must be winter growing season! And while you’re singing to your carrots and tending to your silver beets - have you considered adding beneficial fungi to your plants?

Fungi can transform your entire garden bed – from drought resistance to disease protection to larger, plumper vegetables. It can create the kind of booming broccolini and perky peas that Sue next door will be lusting over.

A basket of freshly harvested vegetables

You see, fungi and plants have a symbiotic relationship. The plant photosynthesises and gives the fungi simple carbohydrates, and the fungi provide the plant with water and nutrients from the soil. And there’s a word for this relationship: Mycorrhizal fungi.

Mycorr-what?

Mycorrhizal fungi, that’s what. Which in the classic Greek word, literally translates to “mushroom” and “root.” But to understand mycorrhizal relationships and beneficial fungi for gardens – we must first understand mycelium.

When we think of a mushroom, we typically think of the fruiting body. But there’s a whole lot more happening beneath the surface. Mushroom mycelium is the vegetative part of the fungus – consisting of branching hyphae. This creates an underground web (similar to a root system) that interlinks with each other and plants.

A cartoon of a tree, showing the root system and mycelium interacting beneath the surface

Yes – back to the plants.

Mycorrhizal relationships can have a profound impact on how plants grow. And to be exact, 80-90% of plants benefit from mycorrhiza. With better access to water, oxygen and nutrients, plants can become resistant to diseases, such as those caused by microbial soil-borne pathogens, and they can also become resistant to the effects of drought. Neat.  

While mycorrhizal fungi are often naturally present in the soil, chemicals, pesticides and tilling have the potential to strip the soil of this goodness. Effects can vary depending on the type of substance and dosage.

By adding mycorrhizal fungi to your garden bed, you’re giving your plants a fighting chance against nutrient-poor soils. And heck, what gardener wouldn’t want that?

Types of Beneficial Fungi for Plants

Now we’re getting our hands dirty.

There are several different types of Mycorrhiza, but endomycorrhiza and ectomycorrhiza are the two superstars.

“Ecto” means “outer” – as the fungus externally grows between the plant roots. These relationships are less common, benefitting around 10% of plant species.

“Endo” on the other hand, means “within” – as the fungus penetrates the root of the plant. This mycorrhizal relationship is the most common, occurring in up to 80% of plants.

Mushroom mycelium growing through soil, beneficial fungi for gardens

These mycorrhizal fungi are then broken down into different species, which each have different functional benefits for the plant. One host plant can have relationships with a whole range of different mycorrhizal fungi – even at the same time (but we’re not here to judge).

Research suggests that having a whole range of mycorrhiza (rather than a single species) has greater benefits for the plant. That’s because using only one mycorrhiza fungi will limit its ability to be compatible with all plants.

And a fair warning: some companies out there will sell mycorrhizal fungi with only one species, so when you’re shopping around at your garden store, remember to look for a nice blend.

So, what are the benefits of fungi?

How Do Fungi Help Plants?

So now we know that fungi are good for your garden. And we know it’s beneficial to have a range of mycorrhizal relationships. But what exactly can mycorrhiza do to transform your garden bed?

Just to name a few: 

  • Draw more water from the soil, which can, in turn, improve drought tolerance
  • Draw more nutrients from the soil (such as organic nitrogen, phosphorus and iron) which can produce plump, hearty and vigorous plants
  • Increase plant establishment and survival and boost crop yields
  • Protect against disease (such as microbial soil-borne pathogens)
  • Sequester more carbon
  • Control erosion
  • Bigger root growth and root surface area
  • Reduce the need for fertilizers – creating healthier, nutrient-rich soil

A garden bed with beneficial fungi, growing beetroot leaves

Do You Need Soil Fungi?

In a perfect world, you wouldn’t need to add fungi to your garden soil (fungal soil is all around us). But common occurrences like chemical use, pesticide use, tilling, crop rotation, fumigation, obnoxious weeds and fallowing can leave soil fungi a little high and dry.

While your backyard garden can function beautifully without the use of mycorrhizal fungi, adding it may help to restore your soil, boost your production and make plants less reliant on other fertilisers.

There are several mycorrhiza products on the market, which can be used year-round. Mycelium will naturally grow and multiply, so reapplication may only be necessary once a year! It’s best to add the mycorrhizal powder to the soil before planting.

It’s basically the perfect garden love story, isn’t it? The beautiful, symbiotic relationship between plants and fungi. And your vegetables lived happily ever after.

Mushroom mycelium growing through soil

Written by Shane and Ash, the scientists, mushrooms farmers and garden enthusiasts behind Natura Mushrooms. 

Resources:

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6587947/

https://www.anbg.gov.au/fungi/mycorrhiza.html

https://mycorrhizae.com/mycorrhizae-four-species-is-better-than-one/

https://mycorrhizae.com/