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Friendly fungi facts

Rootgrow mycorrhizae are fungi that coexist in the soil with plant root systems. They have a symbiotic relationship in which the fungi provide the host with additional water and nutrient in exchange for the plant's waste products (mainly starches) that the fungi require to grow.

Mycorrhizae grow vastly more rapidly than roots and so they can increase the effective root area of a plant many times in only a few weeks.

It is therefore to use Rootgrow™ on new plants because neither compost grown nor barerooted plants are likely to have any friendly fungi on their roots. It will take a couple of years for the two to naturally find one another in the soil after planting.

The mycorrhizae contained within Rootgrow rapidly enhance a plant's root system so it:

  • Finds more food and more water more quickly
  • Needs less fertiliser
  • Establishes more quickly and is less likely to fail
  • Has increased tolerance to drought and difficult soil conditions

Because mycorrhizae are alive and reproduce, one application will support a plant for its entire lifetime. You can buy Rootgrow here in powdered and gel form and in small and large packs.

Rootgrow™ and the Royal Horticultural Society

When Rootgrow was first introduced to RHS gardeners in 2000 it appeared to be an ideal product to fit in with their desire to grow plants with less dependence on chemical fertilisers and using natural, truly organic methods. RHS gardeners then went on to rigorously evaluate Rootgrow to see just how well it actually worked.

After 10 years the RHS made the unprecedented move of formally endorsing and licensing Rootgrow, the first time a planting aid had ever been deemed worthy of this type of endorsement.

RHS gardeners found that plants grown with Rootgrow:

  • Had superior establishment with better natural vigour
  • Overcame replant problems more successfully
  • Had better developed root systems
  • Were better able to cope with conditions of drought.


Specific benefits for roses

Over the last 10 years the benefit of treating roses with Rootgrow has been well documented. The mycorrhizal fungi in Rootgrow establish quickly around the rose roots (especially in the case of bare root roses or roses that have been recently lifted and containerised) and begin transferring water and nutrients to the plant. This enables a rose to overcome replant problems, eliminating the need to replace top soil in areas where roses had been grown before.

Rootgrow is also very effective at extracting P (Phosphorous) from clay soils and this enables roses to flower earlier and better throughout the growing season.

Rootgrow is recommended by virtually all UK rose growers

Specific benefits for vegetables and grow-your-own

There is a growing trend towards grow-your-own (GYO) and Rootgrow is the perfect product for this, especially for first time gardeners. Young plants can have a high mortality rate and this can be disheartening for beginners. However, Rootgrow fungi are proven to reduce mortality amongst new plants.

It is also totally safe and natural which is of particular concern when GYO as many gardeners don’t want to use inorganic or synthetic fertilisers. Rootgrow is not a fertiliser – it simply enables the plant to better access the nutrients in the soil, so it is very important to still prepare the soil well and top it up with organic matter each year and (in the case of very hungry plants such as tomatoes and sweetcorn) supplement their diet with natural organic fertilisers. These fungi are completely natural and organic and native to UK soils and so are suitable for organic growing

Up to 20% greater yields on some crops

Rootgrow-Trial Without rootgrow, the tree is passive, and our assistant is in no danger, even at close range. With rootgrow, it becomes aggressive, and our assistant is no longer safe from it standing 2m away.

Specific benefits for trees and specimen plants

Many larger trees and specimen plants can struggle to make good growth in the early years after planting. This is almost invariably due to inadequate water being available after planting. A contributory factor is that the roots of a bareroot tree take time to establish. So, immediately after planting, the roots are catching up with the amount of top growth they have to support.

If Rootgrow is used the plant will have access to a greater volume of soil (and therefore water and nutrient) much faster than normal and this helps to balance out the root to shoot ratio.

Recommended by UK Highways Agency for Urban Planting

Specific benefits for evergreen hedging

These can include hedges of Buxus (Box), Taxus (Yew), Ilex (Holly) and many others. In many cases these hedges are slow to establish, as it is harder for the plant to grow robust evergreen leaves rather than deciduous ones.

It is particularly important to reduce losses from the start, as filling in gaps in hedges can lead to very unsatisfactory results due to differential growth rates. In some cases, such as Box and Yew, replaced plants may also look quite different from the originals.

Rootgrow can reduce mortality rates in large scale hedge planting to under 1%

4 thoughts on “Friendly fungi facts”

  • Helen Smith

    As a student of agricultural science at the University of Nottingham in 1960, my honours dissertation was on the subject of mycorrhiza growing on the roots of grass species. We had no idea at that stage what a vital role they play in plant nutrition.

  • R. Jenkins

    Just for see if Rootgrow made a difference, when I planted two silver birch trees in 2011 I treated them in exactly the same way with the exception of adding rootgrow to one. I am not good with a camera but the one with rootgrow is about 2 feet taller than the other and just looks "bigger". It has more branches a thicker trunk and carried more leaf this summer. I have used rootgrow on a new rose border I planted last week and am convinced that it is brilliand stuff.
    Rob Jenkins

  • Darren

    Great to hear it Rob - we've had similarly impressive results with Rootgrow in tests at the nursery!

    Could you send us a photo of the birches? You can email me at


  • Andrew

    Three years ago I bought and planted 800 hedging plants and 12 trees with Rootgrow and lost 2 hedging plants. Last year I planted an additional 17 trees and lost 3 as I did not have any Rootgrow when I planted them. I am tempted to dig the surviving 14 up and put Rootgrow on their roots.(just kidding). I will not plant ever again without rootgrow.


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