If you’re looking for a simple, natural way to give your plants a head start, you might want to consider adding mycorrhizal fungi to your gardening toolkit. It sounds a bit like something out of a sci-fi novel, but this fungus has been around for hundreds of millions of years, quietly partnering with plants to help them thrive. Whether you’re planting trees, shrubs, vegetables, perennials, or even wildflowers, there’s a good chance mycorrhizal fungi can help you grow stronger, healthier plants—with less watering, less fertilizing, and more resilience overall.
What Is It?
Mycorrhizal fungi (pronounced my-core-RYE-zal) form a symbiotic relationship with plant roots. The word itself comes from Greek: “myco” meaning fungus, and “rhiza” meaning root. Essentially, these fungi attach themselves to the roots and grow outwards into the soil, creating a network of fine threads (called hyphae) that act like an extension of the plant’s root system.
This network brings water and nutrients—especially phosphorus and micronutrients—back to the plant. In return, the plant shares a bit of its sugars with the fungi. It’s a beautiful little partnership where everyone wins.
What Kinds of Plants Benefit?
Most plants do. In fact, about 90% of plants naturally form relationships with mycorrhizal fungi. That includes:
- Trees (like oaks, pines, maples, fruit trees)
- Shrubs including roses
- Perennials
- Veggies (especially tomatoes, peppers, corn, and beans)
- Grasses and wildflowers
However, there are a few exceptions. Members of the brassica family—like broccoli, cauliflower, cabbage, and mustards—generally don’t form mycorrhizal associations. So no need to use it for those. But for everything else, you’re likely to see benefits.
How to Apply It
Here’s the most important thing to know: the fungi must come into direct contact with the roots. If it doesn’t touch the roots, it won’t colonize and won’t work.
You’ve got a couple of easy options:
- Sprinkle it in the planting hole. Just before you drop in your seedling or transplant, dust a bit of the mycorrhizal powder or granules right where the roots will go.
- Make a root dip paste. Mix the powder with water to create a muddy slurry, then dip the roots of bare-root plants right into it before planting.
- Coat rootballs. For container plants, gently pull apart the bottom of the root ball, sprinkle some fungi directly in there, then replant.
That’s it. One application at planting is typically all you need. Once the fungi have colonized the roots, they’ll stick around and grow with the plant, continuing to help for months or even years depending on the species.
What Kind of Difference Does It Make?
It’s not magic, but sometimes it sure feels like it. You might see:
- Faster establishment. Plants settle in quicker, especially in poor soils.
- Improved growth. Stronger roots, lusher foliage, better flowers or fruit.
- Reduced need for fertilizer. The fungi help the plant access nutrients that would otherwise be unavailable.
- Better drought resistance. The fungal network helps pull in more moisture during dry periods.
- Increased disease resistance. Healthy, well-fed roots are more likely to fend off soil pathogens.
In the long run, using mycorrhizal fungi can lead to less work and better results—especially in challenging conditions like compacted soil, dry climates, or areas with low fertility.
Why Bother?
Because it’s simple, natural, and effective. Mycorrhizal fungi have been quietly helping plants grow for millions of years—long before fertilizers and irrigation came along. By reintroducing this ancient ally to our gardens, we’re tapping into a system that’s already designed to support healthy plant life.
So next time you’re planting something—whether it’s a prized apple tree or a humble marigold—give it a boost. A little sprinkle of fungi can go a long way.
Happy planting!
