Mycorrhizae fungi coexist with plant root systems in a symbiotic relationship: the fungi give the plant water and soil nutrients in exchange for the sugars that plants make by photosynthesis
Fungi grow much faster than roots, so they can increase a transplanted plant’s effective root area many times over in only a few weeks, during which time the roots themselves have barely grown.
These fungi are present naturally in any soil where plants are growing, but they are easily destroyed by digging and transplanting.
If you do not add Rootgrow at planting time, the mycorrhizal fungi in the soil will eventually colonise your new plant, but this could take a year or two.
By putting Rootgrow fungi on the roots, you ensure that there is an explosion of fungal activity from day one, giving your plants the best possible start.
Rootgrow’s mycorrhizal fungi rapidly enhance a plant’s root system so it:
- Finds more nutrients and water
- 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.
Rootgrow is not a fertiliser, but don’t add fertiliser at planting time!
Rootgrow simply enables your plant to better access the nutrients in the soil, so digging in well rotted organic matter is still important, as is mulching the surface each year.
However, you should not add fertiliser to the hole at planting time, whether organic like Bonemeal, or inorganic like Growmore. They will stifle the fungi.
Rootgrow and the Royal Horticultural Society
Rootgrow is the only plant / soil treatment ever to have been licensed by the RHS, after about 10 years of testing it on a wide range of plants, including trees, hedging, roses, and fruiting plants.
It is totally safe, natural, and organic.
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
- Had much lower levels of transplant failure, under 1% in large scale hedge planting
Specific Benefits for Roses
Rootgrow is recommended by all major UK rose growers
- Rootgrow helps to prevent “replant sickness” problems, potentially eliminating the need to replace topsoil in areas where roses had been grown before.
- Rootgrow is effective at extracting Phosphorous from clay soils, which enables roses to flower earlier and better throughout the growing season.
“At Rozenhof Lottum, one of the five national rose gardens for the certification of “Toprozen” in
the Netherlands, a mycorrhiza root dip was used when planting new rose cultivars in test
compartments in early May 2007, actually too late for planting bare-root roses. In one
compartment mycorrhiza was left out. The roses of all mycorrhiza treated compartments survived
and developed reasonably, while the roses in the untreated compartment died of and were
removed in August”“The well-known garden architect Ineke Greve, Huys de Dohm, Heerlen, had a rose replant
problem in 2005/2006 when creating new borders in the “Long Garden” of her estate. In autumn
2006 she decided to repeat the planting with new roses without changing soil but using
mycorrhiza. In June 2007 when her gardens were open for visitors the young roses looked healthy
with many buds and flowers and the lady was very content with the result and started to promote
the product”
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 usually 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
Popular evergreen hedges like Box, Yew, and Holly are slow to establish, and have higher failure rates than deciduous plants because they are in growth almost all year. They benefit the most from the support that Rootgrow provides.
OK, That’s All Very Well, But Are There Alternatives?
Mycorrhizal fungi are “everywhere”, and they are most abundant in woods & forests:
- Go to your nearest wooded area with deep leaf litter
- Scrape off the top layer until you reach well rotted leaves mixed with some soil
- This should be rich in mycorrhizal spores
- Chuck it in the planting hole and hope for the best!
Further Reading
Robert Pavlis has a great series of articles investigating the claims of Mycorrhizal products in North America, at least some of which appear to be a complete waste of money! Others seem like they probably do help, but scientific studies are lacking.
- Mycorrhizal Inoculant Investigation – Do They Work?
- The Mycorrhizal Fungi Myth
- Mycorrhizal Fungi – The Latest Scientific News
Rootgrow, however, has been trialled by the RHS, and several other studies that show its efficacy on woody plants (like we sell), but not really for annual crops like wheat:
- Effect of arbuscular mycorrhizal fungi on yield of different trees and shrubs
This 2001 study by Plant Works, the company that makes Rootgrow, delightfully found that, in addition to greatly increasing growth rates and almost preventing tree failure, Rootgrow made the plants significantly “booshier”, which is really the whole point of growing trees as far as I’m concerned. - Use of Arbuscular Mycorrhizal Fungi to Improve Strawberry Production in Coir Substrate
This 2016 study found that Rootgrow increased yield and the number of Class I fruits, particularly under stress conditions of water or nitrogen deficiency. Note that coir is a soil-free growing medium, in which the fungi struggled to colonise the strawberry roots. - Experimental evaluation of biological regeneration of arable soil: The effects of grass-clover leys and arbuscular mycorrhizal inoculants on wheat growth, yield, and shoot pathology
This 2022 Study found that Rootgrow had no impact on wheat (which is an annual crop, not a woody perennial), and in some cases reduced yields. Leaving fields fallow for three years with cover crops of clover and grass gave the best results. - Mammoth Round Up of Scientific Studies & Unofficial Trials
Only one of the studies is about Rootgrow specifically (see page 289), tested on Common Alder, showing a:- 16% lower mortality rate
- Significant increase in root collar diameter leaf biomass.
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.
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
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 [email protected]
Cheers,
Darren
Hi,
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.
A