Rootgrow fungi are so effective that they are "as good as essential" for planting perennial trees and shrubs, and bulbs, especially on poor or depleted soils.
It didn't attain widespread garden use until the 1990's, but now everyone understands that boosting mycorrhizal fungi at planting time is extremely effective.
They form a protective, symbiotic sheath over a plant's delicate feeding roots, which massively increases the availability of many soil nutrients.
You could think of them as a "third party stomach" for roots. If that sounds gross, then call just them Friendly Fungi Buddies, or Mushroom Minions.
Every packet of Rootgrow comes with dosage instructions: remember that you do not mix Rootgrow with any fertiliser, including organic bone meal.
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What is Rootgrow?
Rootgrow, made by Empathy, is a brand of root supplements that helps transplanted plants establish faster, endorsed by the Royal Horticultural Society.
It contains naturally occurring mycorrhizal fungi that would normally colonise tiny seedlings and coat their roots as they begin to grow.
Because these fungi live on the exterior of the roots, they are effectively destroyed when the plant they live on is dug up, bumped around, delivered to you by post, and then stuffed into new soil conditions.
By thoroughly inoculating your plants' roots with Rootgrow at planting time, you ensure that the fungi bounce back fast and start to cover the roots again from day one.
Otherwise, it could take a long time for a useful amount of the fungi to find their way through the disturbed soil to your plants and re-establish themselves.
Rootgrow comes in several formulas, to support bareroot plants, established trees, shrubs, bulbs, and even as coated meadow seed.
How to make your rootgrow go further
The recommended amounts on the packet are for best results, and using more than that will not help.
However, if you are on a budget, the "minimum effective dose" you can get away with and still see real results is around 10-20% of the recommended dose on the packet, depending on the type of roots you are working with.
Especially with tough native hedging planted in fertile, light soil (where the root systems, with their fungi, will join up along the row quickly), you get away with using a lower dose: it is better to give every hedge plant less than give some none if you are running low.
Still, we really do recommend using the correct dose (but not more) for fruiting plants, prized or expensive ornamental specimens, or if your soil was very poor and you improved it by digging a lot of well rotted organic material.
Which Rootgrow Product do I Need?
- Universal Rootgrow is applied to the roots of bareroot and pot grown plants at planting time. It contains a mix of the most common mycorrhizal fungi, known as arbuscular fungi.
- Ericoid Rootgrow is for acidic soil loving plants such as Blueberries. It contains both arbuscular and ericoid fungi, and no harm will come to your plants if you use Universal instead of Ericoid, it will just be slightly less effective (and using more won't change that).
- Bulb Starter Rootgrow is especially designed for flower bulbs and dahlia tubers: it is Universal Rootgrow with added humates (organic acids) that bulbs love, so there is no harm in using Universal Rootgrow instead.
- After Plant Tree & Shrub is a fertiliser that you top dress over the soil after planting, during the growing season, not at planting time.
It is not a substitute for using Rootgrow at planting time, but if for some reason you were unable to use Rootgrow at planting time, it's the next best thing.
- Mini Meadow is a packet of native British wildflower seeds enriched with mycorrhizal fungi to kick-start a wildflower area in your garden.
How do you use Rootgrow mycorrhizal fungi?
Follow the instructions on the packet.
Do not use bonemeal or any other fertiliser in the planting hole if you are using Rootgrow: spread it over the soil after planting instead.
Rootgrow must be applied either directly onto the roots, or right underneath them in the planting hole.
For plants with woody, non-fibrous roots, a gel helps the Rootgrow stick to them.
How do you use Rootgrow Afterplant?
Rootgrow Afterplant is a fertiliser (NPK 7.8 - 3.2 - 8.1, also contains Magnesium), enriched with mycorrhizal fungi, made with seaweed and alfalfa extract, and sulphate of potash.
It is used as a top dressing that you spread over the soil around an establishing tree or shrub during the growing season between Spring and late Summer.
It is not a substitute for using Rootgrow at planting time, but if you did not use Rootgrow at planting time then it's the best thing to help.
How quickly does Rootgrow work?
After application, Rootgrow gets to work immediately, and the results will become apparent in the first two growing seasons.