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Growmore or fruit tree fertiliser: which should you use?

Updated: October 2026

You already have a bag of Growmore in the shed, but a small bottle labelled fruit tree booster suggests that a specialist product will do more. For most established fruit trees in open ground, a suitable Growmore-type granule is the conventional spring answer; a named liquid is not automatically an upgrade. The decision depends on the declared nutrients, directions, tree setting and how often you are willing to feed. Our main [fruit tree fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/fruit-tree-fertiliser) contains all five products from these listings, while this page compares the two relevant approaches.

You already have a bag of Growmore in the shed, but a small bottle labelled fruit tree booster suggests that a specialist product will do more.

Our top picks

Farmer's Secret Farmer's Secret fruit tree booster 237 ml

Best overall

Farmer's Secret Farmer's Secret fruit tree booster 237 ml
9.2/10about £19.55
View offer
Miracle-Gro Miracle-Gro Performance Organics fruit & veg 1 kg

Preis-Tipp

Miracle-Gro Miracle-Gro Performance Organics fruit & veg 1 kg
9.2/10about £7.99
View offer
Topline Topline Grownmore 8 kg

Alternative

Topline Topline Grownmore 8 kg
9.0/10about £23.99
View offer
On this page
  1. 1.What Growmore does for a UK fruit tree
  2. 2.Topline granules versus Farmer's Secret liquid
  3. 3.When the Growmore-type bag is enough
  4. 4.When a fruit-tree bottle is not an upgrade

What Growmore does for a UK fruit tree

Growmore is a balanced general fertiliser traditionally sold with equal proportions of nitrogen, phosphate and potash. Familiar branded UK products commonly declare 7-7-7, but the name alone is not a guarantee that every similarly named listing has that analysis. Nitrogen supports leafy growth, phosphate contributes to root development and potash supports flowering and fruiting. RHS fruit-tree guidance includes Growmore as a method for established apples, pears, cherries, plums and peaches. It is measured in grams per square metre and spread over the rooting area in late winter or early spring, rather than poured against the trunk. A regularly mulched tree growing and cropping normally may not need extra fertiliser. Read the application process in our how to feed fruit trees guide before opening either product.

Topline granules versus Farmer's Secret liquid

The Growmore-type product in this set is Topline Grownmore, an 8 kg granular pack at £23.99. It names fruit trees and shows 4.5 out of 5 from 136 amazon.co.uk reviews. The listing says equal proportions and contains a 20:20:20 field in the product data, but it does not display a statutory NPK declaration. It must not be described as standard 7-7-7 Growmore without confirmation from the current pack. The specialist comparison is Farmer's Secret fruit tree booster, a 237 ml liquid at £19.55. According to the product data, dilute one teaspoon in a gallon of water and apply weekly along the drip line. It shows 4.6 from 2,048 reviews, yet the Amazon reviews are from the United States and the directions use a US gallon. The listing also lacks an NPK declaration. These are not equivalent quantities. Topline is a large multipurpose sack, whereas Farmer's Secret is a small concentrate tied to a weekly watering routine. Several UK Amazon reviews mention split or leaking tubs. For wider product matches, see the best fruit tree fertiliser in this set.
Farmer's Secret Farmer's Secret fruit tree booster 237 ml

Testsieger

Farmer's Secret Farmer's Secret fruit tree booster 237 ml
9.2/10about £19.55
View offer

When the Growmore-type bag is enough

Choose the bag when you have established fruit trees in the ground and can use the remaining granules elsewhere according to the label. Buying a specialist bottle merely to change the wording on the front adds cost without demonstrating a different outcome. The fruit tree fertiliser buying guide explains how to check the label. Inspect Topline's tub on delivery because split-container complaints recur in the Amazon reviews.

When a fruit-tree bottle is not an upgrade

A bottle is not an upgrade when the tree is a mature, mulched specimen in soil and the proposed benefit is only a specialist title. Farmer's Secret does not show an NPK on the listing, its Amazon reviews are from the United States and its weekly US-gallon routine is more demanding than a seasonal granular application. A larger rating count cannot correct those mismatches for a UK gardener. Liquid does have a legitimate place for a tree in a container. UK GROW is the one-litre fruiting liquid in the wider set and names apples, but its 4.8 average is based on only 11 reviews and the listing omits the cap dose. That is a separate patio decision, not a third contender in this comparison. Neither balanced feed nor a specialist bottle replaces every nutrient correction. RHS guidance separately discusses sulphate of potash for dessert apples at intervals, and magnesium deficiency has its own treatment.

Common questions

Can Growmore feed a fruit tree?
Yes, a suitable Growmore product is an established option for fruit trees in the ground. Confirm that your pack has a declared analysis, names the use and gives a rate you can measure. Apply it over the rooting area at the appropriate season rather than piling it against the trunk.
Is Topline the same as 7-7-7 Growmore?
The Topline listing does not establish that. It says equal proportions and contains a 20:20:20 field in the product data, but no statutory NPK declaration is shown. Do not import the 7-7-7 analysis from another brand; inspect the current Topline pack before use.
When is a fruit-tree liquid worth buying?
A liquid is worth considering for a container tree or when regular watering makes precise dilution convenient. It should provide clear metric directions and an appropriate crop claim. The words fruit tree alone do not make a bottle more suitable than a balanced granule for an established tree in soil.
Do I need extra potash with Growmore?
Not automatically. RHS guidance gives sulphate-of-potash treatment for particular apple situations, but adding it without considering the tree and soil can be unnecessary. Treat potash as a separate, measured decision rather than assuming every Growmore application requires another product.
Can I use Growmore in a pot?
Only if the product label gives a container rate and you can measure it accurately. Concentrated granules are easy to overapply in limited compost, while a suitable liquid is often easier to control during watering. Container apple feeding is a different routine from an orchard spring dressing.
Which option matches a March dressing?
The Growmore-type granule is the closer format for a late-winter or early-spring dressing around an in-ground tree. Farmer's Secret is framed as a weekly liquid programme. In either case, follow the exact label and first check whether the tree actually needs feeding.

Related pages

Fruit tree fertiliser for apple trees

Fruit tree fertiliser

Best fruit tree fertiliser UK: match the garden job

Fruit tree fertiliser buying guide: form and label

How to feed fruit trees in the UK: rate and the ring

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the five amazon.co.uk listings in this comparison. There is no laboratory test. Topline is not confirmed as statutory 7-7-7. Farmer's Secret review texts in the file are from the United States. No listing here is claimed to double a crop.

  1. RHS, Fruit trees: feeding and mulching (retrieved 23 October 2026)
  2. RHS, How to grow apples (retrieved 23 October 2026)
  3. RHS, How to grow pears (retrieved 23 October 2026)
  4. RHS, Fertilisers: types and uses (retrieved 23 October 2026)
  5. GOV.UK, Manufacturing and marketing fertilisers (retrieved 23 October 2026)
  6. Fertilisers Regulations 1991, Schedule 2, paragraph 6 (retrieved 23 October 2026)
  7. GOV.UK, Nitrogen fertilisers in nitrate vulnerable zones (retrieved 23 October 2026)
  8. Gardeners' World, Essential apple care (retrieved 23 October 2026)