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Growmore vs Miracle-Gro continuous release for UK pots

Updated: October 2026

You can have an 8 kg Growmore bucket in one tab and a coated Miracle-Gro twin pack in the other, and both titles say plant food granules. Growmore vs Miracle-Gro continuous release is a habit decision: a repeatable uncoated dressing versus a once-in-spring coated pack. They are not the same cost per season and they are not interchangeable on ericaceous shrubs. Prices for both listings stay 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. Those listings 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.

You can have an 8 kg Growmore bucket in one tab and a coated Miracle-Gro twin pack in the other, and both titles say plant food granules.

Our top picks

Miracle-Gro Miracle-Gro Continuous Release All Purpose, 900 g (pack of 2)

Best overall

Miracle-Gro Miracle-Gro Continuous Release All Purpose, 900 g (pack of 2)
9.2/10about £11.94
View offer
Westland Westland Boost Slow Release Plant Food 2kg

Rank 2

Westland Westland Boost Slow Release Plant Food 2kg
9.0/10about £11.64
View offer
Topline Topline Growmore plant-feed granules 8 kg

Alternative

Topline Topline Growmore plant-feed granules 8 kg
9.0/10about £23.99
View offer
On this page
  1. 1.What each granule actually does
  2. 2.Plots, pots and a season’s work
  3. 3.Cost, leftover coating, and when not to use either
  4. 4.Which habit to buy

What each granule actually does

Westland’s Growmore page describes an immediate-release 7-7-7 feed, applied every four to six weeks. It is not a slow-release coating. Topline’s 8 kg tub at about £23.99 repeats that February-to-October interval as a base or top dressing. The Amazon mixing field prints 20:20:20, and a review says 7-7-7. Treat the field as a clash, not as the analysis. Nutrients are available when you apply them, so you come back in a month. A coated granule does the opposite. Love The Garden describes a temperature-controlled coating that releases when the soil is warm enough for growth. Miracle-Gro’s twin pack at about £11.94 is one spring application for the season. Westland Boost at about £11.64 claims six months on 2 kg. The Royal Horticultural Society treats Growmore as a dry inorganic feed and coated granules as controlled-release. Shops say slow release for both. Read the interval, not the adjective.

Plots, pots and a season’s work

A plot you already walk is the Growmore site. You can time a dressing to planting or to a hungry row, and skip a round if June is lush. You may open the tub several times between February and October. That is work, and it is also control. Baskets and patio pots are the coated site. Mix prills in April, or scatter once and water in. Miracle-Gro reviews mention no diluting and no strong smell. A coated pack replaces a weekly liquid for people who will not do that. It does not replace an ericaceous jar. Do not stack a Growmore handful on a full coated mix. If you already mixed Miracle-Gro at potting, leave Growmore for open ground. Application is on how to apply plant food granules.
Miracle-Gro Miracle-Gro Continuous Release All Purpose, 900 g (pack of 2)

Testsieger

Miracle-Gro Miracle-Gro Continuous Release All Purpose, 900 g (pack of 2)
9.2/10about £11.94
View offer

Cost, leftover coating, and when not to use either

About £23.99 buys 8 kg of interval feed. About £11.94 buys 1.8 kg of coated season feed. About £11.64 buys Westland Boost’s 2 kg. The listings do not give a rate, so these are not costs per square metre. Topline’s 2 kg six-month tub at about £17.99 is the expensive way to buy that wording. Leftover shells on the Miracle-Gro twin pack are coating, not proof the plant was unfed. One reviewer returned a pack because the coating would not break down. If that residue is a deal-breaker, use Growmore and accept the monthly work. Use neither pack on lime-hating shrubs. That job is ericaceous plant food granules.

Which habit to buy

If you will reapply on open ground, buy the Growmore habit. If you will pot once and leave the baskets, buy the coated twin pack. If you will do neither, skip a dearer six-month title with a thinner review sample. Named picks for each habit are on best plant food granules.

Common questions

Is Growmore slow release?
Not on the Westland page that describes it as immediate-release 7-7-7. You reapply every four to six weeks. Amazon titles still say slow release for coated packs and sometimes for Growmore-style tubs. Read the interval, not the adjective.
Which is cheaper over a season?
It depends on the area and the rate, which this comparison does not invent. About £23.99 buys 8 kg of interval feed. About £11.94 buys 1.8 kg of coated season feed. A small balcony is cheaper on the twin pack. A vegetable plot that you would otherwise buy four 2 kg tubs for may be cheaper on the 8 kg bucket.
Which is better for hanging baskets?
The coated pack. Reviewers mix Miracle-Gro continuous-release into compost and leave the baskets. Growmore in a 10 litre pot is easy to overdo if you copy a border handful. Use Growmore on the open ground unless the pack in your hand gives a pot rate you will follow.
Which is better for a vegetable plot?
Growmore, if you will walk the plot from February to October. You can time dressings to sowing and to hungry rows. A single spring coat can still feed a raised bed, but it is the forgetful option, not the plot workhorse.
Why do leftover plastic-looking shells appear?
They are leftover coating from continuous-release prills, a review theme on Miracle-Gro’s twin pack. They do not by themselves mean the feed failed. If that residue is unacceptable, use an uncoated Growmore and accept the monthly calendar.
Can I use both in the same pot?
Only if you have a reason and you keep to one full rate. Do not add a Growmore handful on top of a full coated mix. Most gardeners should pick one habit per container.
What about the Topline mixing field 20:20:20?
The Amazon field prints 20:20:20. A review says the tub is NPK 7-7-7. This page does not call the field the true analysis. Read the carton you receive. Classic Growmore is 7-7-7 oxides on the Westland page.
Does coated mean I never liquid-feed?
It means the pack is sold as the weekly-liquid substitute for pots. Hungry plants can still take a liquid later if the label allows it. It does not mean you add extra granules in July because you can still see shells.

Related pages

Plant granules buying guide

Plant granules

Best granular plant food UK for plots, pots and shrubs

Ericaceous plant food granules for UK acid-loving shrubs

How to apply Growmore granules on beds, pots and roses

Sources

Sources from the research digest; data on file 21 October 2026.

  1. Royal Horticultural Society, Fertilisers: types and uses (retrieved 21 October 2026)
  2. GOV.UK, Manufacturing and marketing fertilisers (retrieved 21 October 2026)
  3. The Fertilisers Regulations 1991, Schedule 2 (retrieved 21 October 2026)
  4. Westland Growmore product page (retrieved 21 October 2026)
  5. Westland Ericaceous granules (retrieved 21 October 2026)
  6. Love The Garden / Miracle-Gro, How fertilisers work (retrieved 21 October 2026)
  7. Miracle-Gro All Purpose Continuous Release pack label (PDF) (retrieved 21 October 2026)