Gardening Advice

What are Mycorrhizae (and why do we care)?

2018-05 What Are MycorrhizaeWe all diligently water and fertilize the plants in our garden to ensure they stay healthy and happy. But here’s an interesting question: how do plants in the wild survive without our help?

Certainly, there’s no fertilizer fairy running around feeding 20-20-20 to every plant in existence. It turns out, plants in the wild have friends in low places, and those friends are called mycorrhizal fungi.

Mycorrhiza refers to the symbiotic (or win-win) relationship that a plant’s roots establish with certain types of fungi. These fungi attach themselves in some way to the roots of our plants and allow them to take up nutrients in the soil that would not otherwise have been available to them. In exchange, plants provide these fungi with a cut of their own energy stores.

Nature is complicated, and nature is weird.

If someone declared that a fungus had attached itself to their favourite plants, we usually (and reasonably) would interpret this as a bad thing. After all, pretty much every garden centre in the country sells fungicides to combat common garden irritants like powdery mildew and black spot.

It’s safe to say not all fungus is bad, and in fact many are incredibly important — Exhibit A being mushrooms! When a tree dies, mushrooms speed up the rate of decomposition and are integral to the process of re-introducing nutrients into the soil of the forest floor. Conversely, mycorrhizae are important for our trees, shrubs, and perennials while they’re still alive, and we can use some types of mycorrhizal fungi in our own gardens to great effect, enhancing many facets of our plant’s health in a way that most fertilizers can’t come close to achieving.

Mycorrhizal fungi are uniquely equipped to provide this service to our plants; this symbiotic relationship has been in existence for millions of years, so these fungi have had plenty of time to perfect their craft. Mycorrhizal fungi grow literally hundreds of times faster than the fibrous roots of our plants, and are so thin they can sneak into little pockets in the soil where regular roots cannot make it. In addition, mycorrhizal fungi produce enzymes that break down soil into its component parts at a faster rate, allowing plants access to naturally-occurring nutrients that otherwise would have taken a lot longer to become available.

At Van Luyk’s, we carry mycorrhizal fungi in a powdered form that can be used at the time of planting in place of conventional synthetic fertilizers. Mycorrhizal fungi are generally superior to conventional fertilizers in our garden because they contribute to a positive nutrient cycle in your soil – that is to say, a healthy mycorrhizal population means you won’t have to fertilize your plants; they’ll find their own food! When you apply a synthetic fertilizer, the plant quickly takes up needed nutrients, but the fertilizer does nothing to enrich the soil. Every time that plant runs out of essential nutrients, you’ll have to fertilize again. And again. And again.

Mycorrhizae Tips

There are few things to bear in mind when you go to use mycorrhizae this spring.

First of all, mycorrhizae are meant to be used instead of synthetic fertilizers. Do not use both. If you use synthetic fertilizer after applying mycorrhizal fungi to your new planting, it will effectively kill the fungi. Our plants will happily gobble up all of the nutrients we provide them with our fertilizer, and, having no immediate need for more nutrition, won’t bother to provide the mycorrhizal fungi with the energy it needs to survive.

Organic fertilizers like muskie, manure, or compost are safe to use.

Some plants are more dependent on high mycorrhizal populations than others. Without getting into too much detail, plants that only grow in well-established forest settings are accustomed to generally higher levels of soil fertility and are the greatest beneficiaries of an application of mycorrhizal fungi at planting time. An example would be most types of flowering dogwood – our staff usually insist that our customers use mycorrhizae instead of regular fertilizer (there’s virtually no price difference, by the way).

For more information on the benefits and drawbacks of synthetic and organic fertilizers, check out this blog post.