Pot and houseplant keeper
You already water houseplants, tubs or baskets and will measure a cap on a routine. The Miracle-Gro liquid twin pack states garden and indoor use and has 3,025 reviews. The listing itself prints no NPK.
Universal Fertiliser Compared
The best universal fertilisers, compared.
Top pick: Doff Liquid Growmore 1 L Best value: Doff Liquid Growmore 1 L – It is the lowest shelf price in the set, at £6.55, with a measure in the cap. The 4.8 rating comes from 86 reviews, and the dose fields disagree. Updated October 2026.
Lee Burkhill (Garden Ninja)Expert source
A universal fertiliser is a compound nitrogen, phosphorus and potassium feed for mixed garden plants. It is a different product from a lawn feed, a tomato feed, a box-tree treatment or an aquarium additive. On amazon.co.uk the useful split is form. Containers you already water suit a dilute liquid. Patio pots you will not feed every week suit coated or slow-release granules at planting. Dug beds suit ordinary granules on a repeat calendar. This page compares six listings from 15 October 2026, priced from £6.55 to £23.99. Each star rating and review count stays with its own ASIN, and a missing NPK stays missing. The Miracle-Gro All Purpose Liquid 1.6 L twin pack is the top pick, with 4.6 out of 5 from 3,025 reviews and a listing that covers the garden and indoor houseplants. Doff Liquid Growmore 1 L is the best-value option at the lowest shelf price, £6.55, with 4.8 from 86 reviews. These scores use listing and review evidence. They are editorial scores, with no laboratory test behind them. For the decision order, see the [universal fertiliser buying guide](/hub/fertiliser-soil-and-bark-mulch/universal-fertiliser/sub/universal-fertiliser-buying-guide).
A universal fertiliser is a compound nitrogen, phosphorus and potassium feed for mixed garden plants. It is a different product from a lawn feed, a tomato feed, a box-tree treatment or an aquarium additive.
22 products checked · 62 hrs invested · +21,400 readers
6 of 6: Best universal fertilisers compared
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1-2 of 6Best overall
7.5/10
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∼ £7
∼ £8
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∼ £24
∼ £9
4.8(86)
4.6(3,025)
4.6(2,641)
4.5(181)
4.5(136)
4.4(281)
Personal buying guide
Which universal fertiliser suits me?
Question 1 of 2
What are you feeding?
The best universal fertilisers in detail
Our view
Doff Liquid Growmore is a 1 litre concentrate with a measure built into the cap, and it is the cheapest bottle in this comparison at £6.55. Its 4.8 out of 5 comes from 86 amazon.co.uk reviews, so the score is high but the sample is small. The listing says it suits all plants indoors, outside and in the greenhouse, and reviewers mention vegetables, hanging baskets and borders, including a visible growth spurt in a border after two feeds. Dose is where it gets untidy. The model field says 7:7:7 and the mixing-ratio field says 1:466, while one reviewer uses one cap to 4.5 litres and another half a cap in about 5 litres. One buyer warns that too much can harm plants, so follow the bottle you receive rather than a figure from a review. It is the best value here if you will feed on a routine, with the caveat that few buyers have reported back.
Pros
- Lowest shelf price in the set at £6.55
- 4.8 out of 5, the highest star rating here
- Measure built into the cap
- Listing covers indoors, outside and the greenhouse
Cons
- Only 86 reviews, so the star rating rests on a small sample
- Dose is unclear: listing says 1:466, reviewers quote caps per can
- One buyer warns that too much can harm plants
Best for: Borders, hanging baskets and greenhouse plants where you want the cheapest liquid feed and will follow the cap marks on the bottle.
Less suitable: Anyone who wants a single, printed dilution rate on the listing or a very large review base.
Specifications
- Model
- Doff Liquid Growmore 1 L
- Brand
- Doff
- Price
- ∼£7
- Customer rating
- 4.8/5(86)
- Feed style
- Liquid concentrate
- Analysis
- 7:7:7
- Dose
- 1:466 (listing)
- Pack size
- 1 L
- Indoor use
- Yes
- Stated use
- Indoors, outside, greenhouse
Common questions
Can you use it indoors?
Yes. The bullets say it is suitable for all plants indoors, outside and in the greenhouse.
How is the dose stated?
The Amazon field says a mixing ratio of 1:466. A review says one cap to 4.5 litres. The bottle has an integral measure.
What happens if you add too much?
A review says to stick to the advised amount because too much can harm plants.
Our view
This twin pack of Miracle-Gro All Purpose Concentrated Liquid gives you 1,600 ml of plant food that you dilute in a watering can, for £7.98 on amazon.co.uk. It has the biggest review base in this comparison, 4.6 out of 5 from 3,025 reviews, and buyers describe healthier houseplants, patio tubs and baskets, with new leaves on one struggling plant after about two feeds. The listing says it can go on the garden and on indoor houseplants, which the granule listings here do not state. Buyers do complain that measuring half or a quarter of a cap per litre feels fiddly for a full can, and several say the 800 ml bottles look three-quarters full. The amazon.co.uk listing prints no NPK, and one reviewer who fed every two to three days saw no change at all. The manufacturer label for model 121175 declares 7-3-5, at half a cap per litre, which is a different recipe from Miracle-Gro soluble powder. Granules work out cheaper per feed for at least one buyer, so this is a liquid for people who already water by hand.
Pros
- Largest review base in the set: 4.6 stars from 3,025 reviews
- Listing says garden plants and indoor houseplants
- Concentrate mixes in a watering can, so a little goes a long way
- Reviewers report new leaves and longer flowering on pots and houseplants
Cons
- No NPK printed on the amazon.co.uk listing
- Several buyers say the 800 ml bottles look under-filled
- Measuring a fraction of a cap per litre is fiddly for a full can
- Needs regular feeding by you, unlike a coated granule
Best for: Houseplants, patio tubs and baskets that you water by hand and are happy to feed on a regular routine.
Less suitable: Anyone who forgets to feed pots, or who wants a printed NPK on the listing before ordering.
Specifications
- Model
- Miracle-Gro All Purpose Liquid 1.6 L
- Brand
- Miracle-Gro
- Price
- ∼£8
- Customer rating
- 4.6/5(3,025)
- Feed style
- Concentrated liquid
- Analysis
- 7-3-5 (label)
- Dose
- Half cap/L (label)
- Pack size
- 1,600 ml (2 x 800 ml)
- Indoor use
- Yes
- Stated use
- Garden and indoor plants
Common questions
Can you use it indoors?
Yes. The listing says it can be used in the garden and on indoor houseplants.
Is it a ready-to-pour feed?
No. It is a liquid concentrate that you mix with water. The pack is two 800 ml bottles, 1,600 ml in total.
Do buyers mention the bottle size?
Yes. More than one review says 800 ml is sold in a bottle that looks like 1 litre.
Our view
Miracle-Gro Continuous Release is a coated granule that you mix into compost or sprinkle on pots, and the listing says one application at the start of spring feeds plants for the whole season. The twin 900 g pack costs £11.94 and holds 4.6 out of 5 from 2,641 reviews. Buyers like that there is no smell and no weekly mixing, and they report hanging baskets, tubs, raised beds and tomatoes and green beans in pots doing well. The listing prints no NPK and no rate. The most specific complaint is that the pellets look like resin or plastic and do not break down in soil, and one buyer returned the tub for that reason. A repeat buyer with a larger garden also found the tub did not last the season. Its secondary Amazon rank is hydroponic nutrients, which does not match the bullets, so treat the pack label as the guide to use.
Pros
- Listing claims one spring application for the whole season
- No weekly mixing or measuring cap
- 4.6 out of 5 from 2,641 reviews
- Reviewers use it in pots, baskets and raised beds
Cons
- No NPK or application rate on the listing
- One buyer says the coating does not break down in the soil
- Did not last the season in a larger garden for one repeat buyer
Best for: Baskets, tubs and raised beds where you would rather mix granules in once than measure liquid every week.
Less suitable: Large gardens, or anyone who dislikes seeing coating left in the compost.
Specifications
- Model
- Miracle-Gro Continuous Release 1.8 kg
- Brand
- Miracle-Gro
- Price
- ∼£12
- Customer rating
- 4.6/5(2,641)
- Feed style
- Continuous release
- Interval
- One spring application
- Pack size
- 1.8 kg (2 x 900 g)
- Stated use
- Plants, one spring feed
Common questions
How often do you apply it?
The listing says one application at the start of spring feeds plants for the whole season.
Do you mix it with water?
The listing does not give a dilution. Reviews describe mixing the granules into compost or sprinkling them into pots, with no weekly mixing.
Is the Amazon form field liquid?
No. The form field says powder. The title says continuous release, and the bullets describe a temperature-controlled coating.
Our view
Westland Boost Slow Release is 2 kg of granular plant food for £11.64, with an instant feed plus a six-month slow-release claim. The 4.5 out of 5 comes from 181 reviews, and buyers use it on begonias and basket displays, roses, tulips, vegetable raised beds and some houseplants. One buyer calls it a useful alternative to liquid feed in containers. The bullets claim high potassium for flowering and fruit but print no NPK, and the duration bullet reads 6-moth on the listing. The dominant complaint is packaging: many reviews say the brittle plastic tub arrives cracked, with the lid loose or the granules in the outer bag. One buyer reports mould and went back to another brand. Many reviewers also say it is too early to judge, so the six-month claim is not yet confirmed by users.
Pros
- Instant feed plus a slow-release claim in one granule
- Reviewers use it on baskets, roses, tulips and raised beds
- Measuring spoon mentioned in reviews
- Listing claims high potassium for flowering and fruit
Cons
- Split or cracked tubs are the main defect across many reviews
- No NPK printed, only a high-potassium claim
- One buyer reports mould
- Duration bullet is misspelt and unconfirmed by reviews
Best for: Baskets, troughs and flower beds where you want a granule instead of a weekly liquid.
Less suitable: Anyone who wants a confirmed NPK, or who is sensitive to a damaged tub arriving.
Specifications
- Model
- Westland Boost Slow Release 2 kg
- Brand
- Westland
- Price
- ∼£12
- Customer rating
- 4.5/5(181)
- Feed style
- Instant plus slow release
- Interval
- 6-month claim
- Pack size
- 2 kg
- Stated use
- Roots, foliage, flowers, fruit
Common questions
Does the listing say it is organic?
No. The page asks the question and the bullets do not answer it.
How long is the slow-release claim?
The bullets say a slow-release feed for a 6-moth nutrient supply. That is the spelling on the listing.
What do reviews say about the tub?
Several reviews say the plastic tub arrived split, with the lid loose or the granules in the paper bag.
Our view
Topline Growmore is an 8 kg tub of ordinary granules for flowers, vegetables, fruit trees and shrubs, at £23.99 on amazon.co.uk. That is about £3 per kilogram, the lowest in this comparison. The listing gives a calendar rather than a rate: apply every 4–6 weeks from February to the end of October, as a base dressing or top dressing, and water before and after in dry weather. Buyers report lusher raised beds and roses after two spring feeds, and say it is easy to scatter and rake in. Two problems recur. The Amazon analysis field says 20:20:20, but a UK reviewer says the pack reads 7-7-7, so the analysis is not settled, and the tub is reported to split and spill granules. With 4.5 out of 5 from 136 reviews, it suits a garden big enough to use 8 kg, not a few pots.
Pros
- Lowest price per kilogram in the set, about £3
- Listing gives a 4–6 week calendar from February to October
- Names flowers, vegetables, fruit trees and shrubs
- Reviewers report lusher raised beds and roses after two spring feeds
Cons
- Analysis disputed: listing field says 20:20:20, a reviewer says 7-7-7
- Split tubs and spilled granules are the repeated defect
- No grams per square metre on the listing
- 8 kg is more than a patio needs
Best for: Beds, borders and a vegetable plot where you can use a large tub over a season.
Less suitable: Small patios and balconies, or anyone who needs the NPK settled before buying.
Specifications
- Model
- Topline Growmore Granules 8 kg
- Brand
- Topline
- Price
- ∼£24
- Customer rating
- 4.5/5(136)
- Feed style
- Base or top dressing
- Analysis
- 20:20:20 vs 7-7-7
- Interval
- Every 4–6 weeks, Feb–Oct
- Pack size
- 8 kg
- Vegetables named
- Yes
- Stated use
- Flowers, vegetables, fruit
Common questions
Which plants does the listing name?
Most types of flowers, vegetables, fruit trees and shrubs.
How often do you apply it?
Every 4–6 weeks from February to the end of October, as a top dressing or a base dressing. In dry weather, water before and after.
Is the analysis 20-20-20?
The Amazon field says 20:20:20. A UK review says the tub is NPK 7-7-7, not 20-20-20. The two statements are not resolved on the listing.
Our view
Goulding General Purpose Granules are a 720 g tub for £9.39 that claims to feed plants for up to six months. At about £13 per kilogram on the listing, it is the most expensive feed here by weight. Buyers find the granules easy to apply, and several report that one application covers the growing season. Wisteria, roses, dianthus and agapanthus are named as responding, and some buyers have bought it again over a couple of years. The listing prints no NPK, no rate and gives 720 g as the unit count against 750 g as the item weight. One buyer says the general-purpose tub matched the rose, tree and shrub tub on the ingredient list, and another saw no benefit on strawberries. At least one pack arrived with no instructions, so check the tub when it arrives.
Pros
- Easy to apply, according to reviewers
- Repeat buyers over a couple of years
- Listing claims up to six months
- Roses and wisteria are named as responding
Cons
- No NPK and no application rate on the listing
- Highest cost per kilogram in the set, about £13
- One pack arrived with no instructions
- Unit count of 720 g does not match the 750 g item weight
Best for: A few flowering shrubs and roses where a small tub is enough and you will read the pack for the rate.
Less suitable: Vegetables, larger gardens, or anyone who needs a printed analysis.
Specifications
- Model
- Goulding General Purpose Granules 720 g
- Brand
- Goulding
- Price
- ∼£9
- Customer rating
- 4.4/5(281)
- Feed style
- Slow release
- Interval
- Up to 6 months
- Pack size
- 720 g (item 750 g)
- Stated use
- Plants and flowers
Common questions
Does the listing say it is pet friendly?
No. The page asks the question and does not answer it.
How long does it claim to last?
The bullets say it lasts up to 6 months.
What pack size is stated?
The bullet and the unit count say 720 g. The item weight says 750 g.
How we compared
We compared six amazon.co.uk listings from 15 October 2026, their UK rating lines, review signals and named public sources. Scores reflect review-count confidence, whether the listing gives a usable analysis and dose or calendar, shelf price per litre or kilogram, fit for the stated use, and listing defects. The figures are editorial scores from those sources.
1
Review confidence
30%Amazon stars count for more when thousands of reviews sit behind them. The same star rating on a small sample earns fewer points.
2
Specification
25%A printed NPK, a clear feed style and a usable dose or calendar are what make a listing possible to buy from. A missing analysis stays missing.
3
Value
20%Value uses the shelf price per litre or per kilogram printed for that pack. It is not a cost per pot.
4
Fit and convenience
15%We record indoor and vegetable wording only when the listing states it, and we set pack size against the garden the bullets describe.
5
Listing consistency
10%Split tubs, a disputed analysis, conflicting weights and a missing instruction sheet reduce the score. They are defect signals, not a quality award.
Independent review
Last updated: October 2026
8 sources checked
Universal fertiliser buying guide
Start with where the plants are and how often you will feed them. A watering-can routine suits a liquid concentrate. One spring application in baskets and tubs suits a coated granule. Beds suit ordinary granules when you will repeat a calendar and can use the pack size. Read the analysis the listing actually prints, and keep a disputed field disputed. A high star rating on 86 reviews is a thinner sample than the same stars on a few thousand reviews.
What is a universal fertiliser?
A universal fertiliser is a compound feed of nitrogen, phosphorus and potassium for mixed garden plants. A lawn fertiliser, a tomato feed, a box-tree treatment and an aquarium additive are different products. The Royal Horticultural Society describes a general compound for ordinary garden use, and it points rhododendrons, camellias, heathers and blueberries to an ericaceous feed. The six amazon.co.uk listings here fall into three patterns.
Best for
- Pot and houseplant keepers who will measure a dose on a routine
- Gardeners who want one granule application in baskets and tubs
Not ideal for
- Ericaceous shrubs such as rhododendrons, camellias, heathers and blueberries
- A lawn feed, a tomato-only feed, or a pack sold as an organic treatment
Mistakes to avoid
- 1
Reading 7:7:7 as equal elements
A 7:7:7 line is an oxide declaration. The RHS shows it is about 7% nitrogen, 3.1% phosphorus and 5.8% potassium, so it leans towards nitrogen. The bag is not split into three equal parts.
- 2
Swapping another product’s analysis
Miracle-Gro soluble powder is a different recipe from the 7-3-5 concentrate, model 121175. Topline’s Amazon field says 20:20:20 and a UK review says the tub is 7-7-7. Leave another brand’s grams per square metre on that other brand.
- 3
Doubling the cap
A review of Doff says too much can harm plants, so follow the marks on the bottle you receive. Rhododendrons, camellias, heathers and blueberries need an ericaceous feed.
What to weigh up
Form, job and pack size
HighThe first decision is the job. Containers you already water suit a liquid you dilute in the can. Patio pots you will not feed every week suit coated granules or a slow-release tub at planting. Dug beds suit ordinary granules as a base dressing or a top dressing. The RHS account of feeding is that open ground with decent organic matter often needs little routine feed, so a large tub is not automatically the right buy. Pack size then has to match the garden in front of you.
Analysis, dose and listing consistency
HighRead the nutrient declaration in N, then P2O5, then K2O. A 7:7:7 oxide line is about 7% nitrogen, 3.1% phosphorus and 5.8% potassium on the RHS figures, so it leans towards nitrogen. The manufacturer label for Miracle-Gro model 121175 declares 7-3-5 and half a cap per litre. The amazon.co.uk listing for that twin pack prints no NPK, so the label and the listing are different texts. The soluble-powder analysis the RHS cites, about 24-3.5-13.3, belongs to that powder.
Which option suits you?
Three typical situations, each with a recommendation from this comparison.
Spring basket planter
You want one application at planting rather than a weekly mix. Miracle-Gro Continuous Release claims one spring feed for the season, with 4.6 from 2,641 reviews. The listing prints no NPK and no rate.
Bed and greenhouse gardener
You can use a large tub across beds and will follow a calendar. Topline names flowers, vegetables, fruit trees and shrubs and costs about £3 per kilogram. The analysis is disputed, and reviews report split tubs.
Common questions about universal fertilisers
Which universal fertiliser is the top pick in this comparison?
The Miracle-Gro All Purpose Liquid 1.6 L twin pack is the top pick in this set. It costs £7.98 and has 4.6 out of 5 from 3,025 amazon.co.uk reviews. The listing covers the garden and indoor houseplants, and it prints no NPK. The manufacturer label for model 121175 declares 7-3-5 and half a cap per litre. The score uses those listing and review figures for these six packs.
How much does a universal fertiliser cost?
On these six amazon.co.uk listings, prices run from £6.55 for Doff Liquid Growmore 1 L to £23.99 for Topline Growmore Granules 8 kg. A bottle or the Goulding 720 g tub sits under £10. The Westland 2 kg tub and the Miracle-Gro continuous-release pack sit near £12. The 8 kg tub is the step up at £23.99. These are shelf prices from 15 October 2026. Price per kilogram is not a cost per pot, and live prices move.
What should I check before buying a universal fertiliser?
Match the form to the plants first. A liquid suits containers you already water. Coated or slow-release granules suit pots you will feed once in spring. Ordinary granules suit beds when you will repeat them every few weeks. Then read N, P2O5 and K2O. If the listing has no analysis, that gap is still there when you order. Check pack size, and look again if a tub is reported split or if 720 g disagrees with 750 g.
Does a 7:7:7 fertiliser mean an equal mix?
A 7:7:7 figure is an oxide declaration. The Royal Horticultural Society shows that 7:7:7 is about 7% nitrogen, 3.1% phosphorus and 5.8% potassium, so the mix leans towards nitrogen. Read the pack as N, then P2O5, then K2O. Doff’s listing uses 7:7:7 in the model field. Keep that figure on Doff’s bottle, and treat an unanswered Amazon question as no declaration at all.
Can I use a universal fertiliser on vegetables?
You can when the pack names vegetables and you accept its limits. Topline names flowers, vegetables, fruit trees and shrubs, on a 4–6 week calendar from February to the end of October, but its analysis is disputed and the tub is 8 kg. A pack that only says all plants has not named vegetables. Fruiting crops often need more potassium than a general mix. Feeds sold for crops are set out in the vegetable fertiliser comparison.
Should I choose a liquid or granules for pots?
Choose a liquid if you already water houseplants, tubs or baskets and will measure a dose on a routine. Miracle-Gro All Purpose Liquid and Doff Liquid Growmore both state indoor use. Choose a coated granule if you would rather apply food once. Miracle-Gro Continuous Release claims one spring application for the season. A six-month line on Goulding or Westland Boost is the listing’s claim. It does not show that the pellet uses the same coating.
What should I do if someone swallows fertiliser?
Store every pack shut, away from children and pets. If someone may have swallowed fertiliser and is seriously unwell, NHS advice is to call 999. If you are unsure, contact NHS 111 and take the pack with you. Rinse eyes and get help if irritation continues. None of these listings states an organic certification or a pet-safety claim. Rhododendrons, camellias, heathers and blueberries need an ericaceous feed.
Our verdict
Form and a readable analysis matter more than a universal title. The Miracle-Gro All Purpose Liquid 1.6 L is the top pick because it has 4.6 from 3,025 reviews and a listing that covers the garden and indoor houseplants, at £7.98. Doff Liquid Growmore 1 L is the best-value option at £6.55, with 4.8 from 86 reviews and a measure in the cap. The Topline 8 kg tub is cheaper per kilogram, but the analysis is disputed and reviews report split tubs. The scores come from listings and reviews.
Best valueView offer
Doff Liquid Growmore 1 L
It is the lowest shelf price in the set, at £6.55, with a measure in the cap. The 4.8 rating comes from 86 reviews, and the dose fields disagree.
Editorial
Editor
UK product comparisonsAmazon listing analysisPublic-source research
Products Compared publishes British-English buying guides based on amazon.co.uk listings and public UK sources. We do not run a lab and we do not invent test scores.
Updated: October 2026
8 sources checked
Guides to universal fertilisers
Guides on what to look for, how to use a product, and common mistakes.
Best universal fertiliser by useWho the top pick is for, and who should skip it.Universal fertiliser buying guideChoose a form and read the label before you buy.Universal fertiliser for vegetablesWhen a general feed is enough for crops, and when it is not.How to use universal fertiliserDilute or scatter, water in, and stop at the pack rate.Liquid versus granulesA liquid habit compared with coated granules for pots.
Related comparisons
Sources
Public UK and manufacturer sources used for this comparison; last accessed 15 October 2026.
- RHS: Fertilisers (retrieved 15 October 2026)
- RHS: Nutrition and feeding plants (retrieved 15 October 2026)
- RHS: Fertiliser labels explained (retrieved 15 October 2026)
- GOV.UK: Manufacturing and marketing fertilisers (retrieved 15 October 2026)
- The Fertilisers Regulations 1991 (retrieved 15 October 2026)
- Miracle-Gro All Purpose Concentrate label 121175 (retrieved 15 October 2026)
- Which?: Controlled-release fertilisers (retrieved 15 October 2026)
- NHS: Poisoning (retrieved 15 October 2026)
Expert source (DIY & tools): Lee Burkhill (Garden Ninja) (external profile) – public expert commentary used as a research source, not as a contributor to our pages.
This article contains affiliate links. If you buy a product through one of these links, we may earn a small commission at no extra cost to you. Our editorial assessment remains independent and is based on amazon.co.uk listing data, customer-review evidence and public sources. We did not conduct a laboratory test.