Rootgrow alternative
Under a third of the cost per pot
A plant from a 2-litre pot takes 2 to 3 g of our powder, against about 19 g of Rootgrow granules. That is 18p to 27p from a 120 g pouch, against 90p from a 150 g pack of Rootgrow.
£6.99 40 g, 13 to 20 plants
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- A fine powder you dust or dip straight onto the roots. Rootgrow is granules in a clay carrier, used by the scoop.
- Pouches from 40 g to 5 kg, at 1 to 1.5 g per litre of root ball.
- No ericoid fungi. For blueberries, rhododendrons and heathers, Rootgrow Ericoid is the one.
Cost per plant
Our powder costs more per gram, but you use far less of it. A plant from a 2-litre pot takes 2 to 3 g of powder, against about 19 g of Rootgrow granules. Find your plant, read across.
| What you are planting | Powder per plant | Dr Forest 120 g, £10.99 | Rootgrow 150 g, £7.20 | Plants per pack, ours / Rootgrow |
|---|---|---|---|---|
| Strawberry runner or plug | 0.1 to 0.15 g | about 1p | 12p to 14p | 800 to 1,200 / 50 to 60 |
| 2-litre pot, rose or shrub | 2 to 3 g | 18p to 27p | 90p | 40 to 60 / 8 |
| 5-litre pot | 5 to 7.5 g | 46p to 69p | £1.80 | 16 to 24 / 4 |
| 10 to 15-litre pot, tree or large shrub | 10 to 22.5 g | 92p to £2.06 | £7.20 | 5 to 12 / 1 |
| Bare-root fruit tree, 4 to 5 ft | 5 to 10 g | 46p to 92p | 29p to 42p | 12 to 24 / 17 to 25 |
Price per gram: Dr Forest 40 g 17.5p, 120 g 9.2p, 250 g 7.2p, 500 g 6.0p, 1 kg 5.5p, 5 kg 5.0p; Rootgrow 150 g 4.8p. Rootgrow costs come from the plant counts it publishes for the 150 g pack, at £7.20. Bare-root trees are the exception: there Rootgrow works out cheaper per plant. Our bare-root figure assumes 5 to 10 litres of roots, our estimate. Prices checked 20 Oct 2026.
Against Rootgrow granules, pack by pack
The same plant from a 2-litre pot, from each pack size. Our powder at 2 to 3 g a plant; Rootgrow at two 10 ml scoops, using the plant counts it publishes for each pack.
| Pack | Price | Per 2-litre pot |
|---|---|---|
| Dr Forest powder, 40 g | £6.99 | 35p to 52p |
| Dr Forest powder, 120 g | £10.99 | 18p to 27p |
| Dr Forest powder, 250 g | £17.99 | 14p to 22p |
| Rootgrow granules, 150 g | £7.20 | 90p |
| Rootgrow granules, 360 g | £12.50 to £12.95 | 66p to 68p |
| Rootgrow granules, 1 kg | £28.00 | 56p |
Rootgrow figures from its published packs and plant counts: 150 g at £7.20, treating 8 two-litre pots; 360 g at £12.50 (rootgrow.co.uk) and £12.95 (hedging.co.uk), treating 19; 1 kg at £28.00 treating 50 (hedging.co.uk). Dr Forest pouches at 1 to 1.5 g per litre of root ball. Checked 20 Oct 2026. Rootgrow is a trademark of its owner; Dr Forest is not affiliated.
Why a powder on the root
Mycorrhizal spores only start a partnership when they meet a growing root, so where the inoculum sits matters. In field trials, its position relative to the roots changed how well it colonised1. Spores stuck directly onto roots made more entry points in the first four weeks, though the gap had closed by fourteen2.
A fine powder can be dusted or dipped straight onto the roots, so it starts in contact. Granules go into the hole and wait for roots to grow to them. We have not found a trial that tests powder against granules head to head, so we do not quote a colonisation figure.
Freshness matters as much as format. In an independent test of 23 commercial inoculants, many colonised poorly or not at all3. We buy in small batches, fresh stock comes in every month, and each pouch carries a 9 to 12 month use-by.
- Afek U, Rinaldelli E, Menge JA, Johnson ELV, Pond E (1990). Mycorrhizal species, root age, and position of mycorrhizal inoculum influence colonization of cotton, onion, and pepper seedlings. Journal of the American Society for Horticultural Science 115(6): 938–943.
- Hung L-L, O'Keefe DM, Sylvia DM (1991). Use of a hydrogel as a sticking agent and carrier for vesicular-arbuscular mycorrhizal fungi. Mycological Research 95(4): 427–429.
- Koziol L, Lubin T, Bever JD (2024). An assessment of twenty-three mycorrhizal inoculants reveals limited viability of AM fungi, pathogen contamination, and negative microbial effect on crop growth for commercial products. Applied Soil Ecology 202: 105559.
When to stay with Rootgrow
- Blueberries, cranberries, rhododendrons, azaleas or heathers. These need ericoid fungi; Rootgrow Ericoid has them and our powder does not.
- You want to buy it today at a garden centre, or prefer a granule and a scoop.
Our powder does not suit brassicas, beetroot, spinach or chard, which do not form the partnership. It is not a fertiliser; feed lightly once growth resumes, with All Purpose 4-4-4 or Liquid Seedling Fertiliser, and keep rock phosphate and bone-type meals out of the planting hole.
Common questions
Is Dr Forest the same as Rootgrow?
No. Both are mycorrhizal fungi used at planting, in contact with the roots. Rootgrow is granules in a clay carrier, used by the 10 ml scoop. Ours is a fine powder with 18 named species, 9 endo and 9 ecto, used at 1 to 1.5 g per litre of root ball.
Why do I use so much less powder than Rootgrow granules?
Rootgrow granules include an inert clay carrier, so a plant from a 2-litre pot takes two 10 ml scoops. Our powder has no fillers, so the same plant takes 2 to 3 g. Compare the cost per plant, not the price per kg.
Does Rootgrow contain ectomycorrhizal fungi?
Rootgrow's product pages say the granules contain mycorrhizal fungi but do not name the species or say which type. Our powder has 9 ecto species, for trees such as beech, oak, birch and pine.
Can I use it with my leftover Rootgrow?
Yes. Finish the Rootgrow at the rate on its label, then use our powder at 1 to 1.5 g per litre of root ball for new plantings. Plants already treated do not need treating again.
More: all brand alternatives · our guide to mycorrhizal fungi · mycorrhizal fungi for a new bed
18p to 27p for a 2-litre pot, against 90p
18 species, endo and ecto. Dust or dip the roots as you plant.
£6.99 40 g pouch
Free UK delivery over £40 · Dispatched in 1 to 2 working days · Hand-blended and packed in Stockport