Out of sight, below the ground, the soil teems with life. Fungi make up a lot of the living matter in soils. They form large underground networks and work with plants to “supercharge” their root systems.
More than 90 per cent of all plant species form associations with mycorrhizal fungi. Scientists are still learning new things about the world under our feet. These new findings show us how important it is to protect the health of our soil by using natural methods like composting and not using synthetic fertilizers.
Mycorrhizal fungi form symbiotic relationships with plant roots, improving their uptake of water and nutrients While best added at planting time, you can also introduce mycorrhizal inoculants to already established plants. Doing so at the right time and in the proper way helps your mature plants reap the rewards of this beneficial fungal partnership.
An Overview of Mycorrhizal Fungi
Mycorrhizal fungi are naturally present in undisturbed soil. But common gardening practices like tilling can destroy these important fungi. Reintroducing mycorrhizal inoculants helps restore populations.
There are two main types of mycorrhizal fungi
- Arbuscular mycorrhizal fungi (AMF) – Most common; forms symbiosis with over 90% of plants
- Ectomycorrhizal fungi (EMF) – Less common; partners with trees like pines and oaks
Once colonized on roots, mycorrhizal hyphae extend into the surrounding soil, absorbing and transporting water, nitrogen, and phosphorus back to the host plant.
Key Benefits Mycorrhizal Fungi Offer Plants
- Increased nutrient uptake, especially phosphorus
- Improved absorption of water
- Enhanced resistance to root pathogens
- Increased tolerance of environmental stresses
- Improved soil structure
Is It Too Late to Add After Planting?
While starting at planting maximizes benefits, you can still introduce mycorrhizal inoculants to established plants. The fungi will begin forming symbiotic associations as plant roots grow and encounter the inoculated area.
However, colonization tends to be less extensive on existing roots compared to seedling roots. So the plant response may be slower and less pronounced. But most plants still derive some advantages from late inoculation.
Tips for Applying Mycorrhizal Fungi After Planting
Follow these guidelines to effectively introduce mycorrhizal fungi around existing vegetation:
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Select an appropriate inoculant – Use a quality product containing live spores or hyphae of appropriate fungi species for your plants. Avoid expired products.
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Loosen soil – Lightly cultivate soil around plants to increase contact between roots and inoculant. Avoid excessive disruption of existing fungi.
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Apply inoculant – Sprinkle granules or mix powders into loosened soil around drip line of plants according to package rates. Or dissolve in water and pour around base.
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Water thoroughly – Ensure good soil moisture to disperse inoculant and stimulate root growth into treated areas. Aim to keep soil consistently moist but not saturated.
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Mulch – Top dressed mulch helps maintain optimal moisture levels for root and fungal growth.
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Avoid over-fertilizing – Excess nitrogen can inhibit mycorrhizal colonization. Use organic fertilizers sparingly.
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Be patient – It may take weeks or months to see benefits, depending on plant, season, climate, and soil factors.
The Earlier the Better!
While existing plants can derive some benefit from late inoculation, starting the root-fungi symbiosis early maximizes the advantages. Follow these tips for best results:
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Add inoculant directly to seeds or cutting bases before planting.
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Sprinkle inoculant in planting holes for transplants.
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Mix inoculant directly into potting mixes for seeds, cuttings, or transplants.
Starting early allows extensive colonization as the roots grow, leading to lifelong benefits. But it’s never too late to introduce mycorrhizal fungi into your garden soil!
The benefits to plants of mycorrhizal fungi
Gardeners can increase the amount of mycorrhizal fungi in the soil naturally by composting, mulching it with well-rotted horse manure, leaving leaf litter on top of the soil, and adding leaf mold on top of that. You can also buy mycorrhizal fungi and add it to the planting hole when planting new plants. This can help plants establish more quickly and boost healthy growth by supplying additional water and nutrients. So, mycorrhizal fungi help plants survive drought, make bigger flowers and crops, fight off diseases, and do well in bad soils or other harsh conditions. The primary beneficiaries of mycorrhizal fungi are woody plants, but other types of plant also benefit. Mycorrhizal fungi also help newly planted roses overcome rose replant disorder.
How to use mycorrhizal fungi
- Buy mycorrhizal fungi in powder, granule, or gel form
- Mycorrhizal fungi are most useful when they are used as a one-time help when planting trees, shrubs, roses, hedging, fruit trees, and perennials with no roots. Mycorrhizal fungi are also helpful for lawns, bulbs, and plants that are grown from seeds.
- For plants grown in containers, mycorrhizal fungi can also help them grow.
- Use powder or granules when planting container grown plants. Add the mycorrhizal fungi to the planting hole and then sprinkle them on the roots of the plants to make sure they get them right away.
- Before you plant bulbs or seeds, sprinkle some mycorrhizal fungi into the soil or planting hole.
- Mycorrhizal fungi is also beneficial for plants growing in containers
- Plants that don’t like lime, like rhododendrons, azaleas, and blueberries, need a certain kind of mycorrhizal fungi.
- When you plant bare-rooted plants (which you can only get in the winter when they are dormant), use gel. Follow the directions on the package to mix the gel with water in a bucket. Then, dip the roots of the plants in the bucket before planting them.
- Do not use chemical fertilizers or organic ones that are high in phosphorus, like bonemeal, because they will stop the mycorrhizal fungi from working.
- Do not use chemical fungicides, weed killers, or pesticides. When not to use mycorrhizal fungi
- If fungicidal chemicals have been used recently, do not use because the fungicide will kill the good fungi.
- Chemical fertilizers inhibit the growth of mycorrhizal fungi
- Avoid using mycorrhizal fungi alone on poor or over-cultivated soil. First, make the soil better by adding a lot of organic matter, like leaf mold, garden compost, well-rotted manure, composted chipped bark or garden shreds, or well-rotted manure.
- Do not apply on soil where brassicas have been grown
4 Ways To Apply Mycorrhizae Inoculant Correctly!
FAQ
How to add mycorrhizae to soil after planting?
When not to use mycorrhizal fungi?
Can you have too much mycorrhizal fungi?
Can you top dress with mycorrhizae?
When should I apply mycorrhizal fungi?
Mycorrhizal fungi should be applied any time you are re-potting or transplanting to give the fungi time to colonize the plant’s root mass and ensure a successful grow. Granular Mycorrhizae and Biostimulants are also beneficial to apply to established plants. Cultivate and blend into soil and make sure to water in well.
Can I use mycorrhizal fungi over a new planting site?
Mycorrhizae is naturally occurring on healthy soil. And transferring a portion of healthy soil containing the fungi from a part of your garden for use in other areas is acceptable. In my experience, spreading a soil container with mycorrhizal fungi over a new planting site is sufficient.
Does mycorrhizal fungi harm plants?
In contrast to synthetic chemicals and common fertilizers, Mycorrhizal Fungi cannot harm your plants if used excessively or frequently. Again for optimal outcomes, follow the product instructions. This is the best method for adding mycorrhizae to the soil. The inoculant is added to the seeds before planting.
Can I plant mycorrhizal fungi from seed?
Mycorrhizal fungi is also beneficial when growing from seed, including lawns, and bulbs Use powder or granules when planting container grown plants. Mix the mycorrhizal fungi into the planting hole and sprinkle onto the plant roots to ensure immediate contact
How do I inoculate plant roots with mycorrhizal fungi?
Inoculating plant roots with mycorrhizal fungi can be approached in various ways. The goal is to ensure that the fungi come into direct contact with the plant roots for successful colonization. I’ve found that adding granular inoculant directly into the planting hole or mixing it with the seedlings’ potting soil can be effective.
Should I spray mycorrhizal fungi around my plant base?
This means applications that allow the fungi to contact roots directly have better success than spraying droplets around your plant base. The symbiotic relationship between mycorrhizal fungi and plants offers several benefits for your garden vegetables, flowers, and fruits.