How to apply Growmore granules on beds, pots and roses
Updated: October 2026
The tub is already in the shed, and the question is how to apply Growmore granules without guessing a handful or leaving prills on dry compost. The pack in your hand sets the rate. A handful is only that brand’s shorthand, and these amazon.co.uk listings almost never print grammes per square metre. Product choice stays on the [plant granules comparison](/hub/fertiliser-soil-and-bark-mulch/plant-granules). This page is from Peter F., the DIY and tools editor, on 21 October 2026. Listings, manufacturer pages and public UK sources were read for this page. There was no laboratory test. A qualifying purchase can earn a commission at no extra cost to you.
The tub is already in the shed, and the question is how to apply Growmore granules without guessing a handful or leaving prills on dry compost. The pack in your hand sets the rate.
The tub is already in the shed, and the question is how to apply Growmore granules without guessing a handful or leaving prills on dry compost. The pack in your hand sets the rate. A handful is only that brand’s shorthand, and these amazon.co.uk listings almost never print grammes per square metre. Product choice stays on the plant granules comparison. This page is from Peter F., the DIY and tools editor, on 21 October 2026. Listings, manufacturer pages and public UK sources were read for this page. There was no laboratory test. A qualifying purchase can earn a commission at no extra cost to you.
Our top picks
| Badge | Product | Method | Interval | Where | Note | Price | Offer |
|---|---|---|---|---|---|---|---|
| Best overall |  Miracle-Gro Miracle-Gro rose and shrub plant food 3 kg carton | Top dress | Twice a season | Roses and shrubs | 9.2 | about £9.99 | View offer |
 Miracle-Gro Miracle-Gro Continuous Release All Purpose, 900 g (pack of 2) | Mix in or scatter | Once in spring | Pots and beds | 9.2 | about £11.94 | View offer | |
| Alternative |  Topline Topline Growmore plant-feed granules 8 kg | Base or top dress | Every 4–6 weeks | Outdoor plot | 9.0 | about £23.99 | View offer |
On this page
Base dressing, top dressing, mix-in
A base dressing goes in before the plant. A top dressing is scattered around plants that are growing, then watered or raked in. A mix-in is stirred through compost at potting-on. Coated granules are sold for mix-in and a single spring scatter.
Westland’s Growmore page, not the Topline listing, uses about 35 g for a handful, about 70 g/m² as a top dressing and about 135 to 140 g/m² as a base dressing. A Miracle-Gro continuous-release label uses a 25 g handful and 25 to 50 g per 10 litres. Weigh one and write it on the lid. Topline’s 8 kg listing says every four to six weeks from February to the end of October, and to water before and after in dry weather. Keep granules off leaves and the crown. If the tub is not chosen yet, use the plant granules buying guide.
Pots and hanging baskets
A 10 litre pot is not a square metre. Copying 70 g/m² into it overfeeds. Use the pack’s pot rate if it has one. Simplyseed’s 3 to 4 g per litre is a rule of thumb from that page, not a rate for these listings.
Mix coated granules through moist compost, or scatter and water in. Organic granules left on pot compost grew mould in reviews. Topline’s six-month listing says water the granules to activate and warns that overdosing can damage plants. If the plant is wilting, water it before you feed it. The two habits are not one method: Growmore or a coated season feed.
A UK calendar and when to stop
Topline’s 8 kg listing is every four to six weeks from February to October. Write the next date on the tub. Coated packs are one application at the start of spring. Westland Boost claims six months, and the listing spells that line 6-moth. Westland’s ericaceous page, not the amazon listing, says March and June at 40 g/m². The 3 kg rose carton is twice a season, at first buds and the second flush, for up to three months.
Stop in winter. Love The Garden says not to feed when plants are not growing. Stop if the plant is waterlogged, frost-lifted or already scorched. The Royal Horticultural Society treats fertiliser as optional on most UK garden soil. Leftover coating shells are not proof the feed failed, and they are not a reason for a second spring dose.
Mistakes that scorch
Doubling the dose because last year’s display was poor is how a pot rose dies in a month, a review on the 3 kg carton. Granules on leaves or dry compost waste the pack or pull moisture from the stem. Growmore on lime-hating shrubs is the wrong jar. Yellow leaves are not always hunger. A split tub poured by eye has already lost the rate. If granules are eaten, if run-off may reach a watercourse, or if a mature shrub still declines after a correct rate and a moisture check, call a professional or NHS 111. Do not invent a gramme rate from the kilogramme on the title.
Common questions
How many grams is a handful?
It depends on the brand. Westland’s Growmore page uses about 35 g. A Miracle-Gro continuous-release label uses about 25 g. Both are manufacturer figures. Weigh your own handful once and write it on the lid. Do not copy either number onto a tub that prints a different spoon.
Do I water granules in?
Yes in dry weather. Topline’s Growmore listing says water before and after. Topline’s six-month listing says water to activate. Coated prills mixed through moist compost still need a watering after potting. Granules left on dry compost sit there and can scorch.
Can I mix them into peat-free compost?
Coated continuous-release granules are often mixed at potting. Growmore is usually a base or top dressing, not a potting-mix additive. Peat-free compost still needs to be moist before you apply. Do not raise the dose because the compost is peat-free.
When do I stop feeding?
Stop in winter, and stop if the plant is not growing, is waterlogged, or already shows scorch. Growmore in these listings ends in October. Coated packs are one spring application. The rose carton is twice a season, not monthly.
What if the compost is dry?
Water first, then apply, then water again. Dry compost will not move nutrients into the root zone, and surface granules can pull moisture from stems. This is the usual hanging-basket fault in a windy May week.
How often for Growmore versus a six-month coat?
Growmore: every four to six weeks from February to October on the Topline listing. A six-month or season-long coat: once at the start of spring, unless the pack you hold says otherwise. Do not run both calendars on the same pot without a reason.
Will granules burn pot roses?
They can if you overfeed. The 3 kg Miracle-Gro rose carton has reviews of a dead pot rose and an overfeed warning. Use the pack rate, keep granules off the stem, and water in. Fast-acting on the bullet is not a reason to heap the planting hole.
Do leftover coating shells mean it failed?
No. Visible shells after a season appear in Miracle-Gro twin-pack reviews. They are leftover coating, not proof the plant was unfed. They are also not a licence to add a second full dose in July.
Related pages
Sources
Sources from the research digest; data on file 21 October 2026.
- Royal Horticultural Society, Fertilisers: types and uses (retrieved 21 October 2026)
- GOV.UK, Manufacturing and marketing fertilisers (retrieved 21 October 2026)
- The Fertilisers Regulations 1991, Schedule 2 (retrieved 21 October 2026)
- Westland Growmore product page (retrieved 21 October 2026)
- Westland Ericaceous granules (retrieved 21 October 2026)
- Love The Garden / Miracle-Gro, How fertilisers work (retrieved 21 October 2026)
- Miracle-Gro All Purpose Continuous Release pack label (PDF) (retrieved 21 October 2026)