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Best geranium fertiliser for pots, once or baskets

Updated: October 2026

Best on a shopping page usually means a laboratory winner. The best geranium fertiliser here is the listing that matches a balcony, a once-a-year habit, or a run of baskets, and the rest are easy to skip. Eight amazon.co.uk rows remain: seven Cultivers sizes and one Fertiligène Osmocote Max tub. Prices are the listing figures from 19 October 2026. The [geranium fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/geranium-fertiliser) holds the full table. A qualifying purchase can earn a commission at no extra cost to you.

Best on a shopping page usually means a laboratory winner. The best geranium fertiliser here is the listing that matches a balcony, a once-a-year habit, or a run of baskets, and the rest are easy to skip.

Our top picks

Cultivers Cultivers organic geranium and flowering plant fertiliser 250 g

Best overall

Cultivers Cultivers organic geranium and flowering plant fertiliser 250 g
10.0/10about £11.62
View offer
Fertiligène Fertiligène Osmocote Max geranium fertiliser 700 g

Alternative

Fertiligène Fertiligène Osmocote Max geranium fertiliser 700 g
9.4/10about £23.00
View offer
Cultivers Cultivers organic geranium and flowering plant fertiliser 1 kg

Best value

Cultivers Cultivers organic geranium and flowering plant fertiliser 1 kg
8.8/10about £15.53
View offer
On this page
  1. 1.A few pots
  2. 2.Feed once
  3. 3.Many baskets
  4. 4.What not to crown

A few pots

Three pots do not need a can you cannot lift. The small end is the 250 g Cultivers granules at about £11.62, the 250 ml liquid at about £13.51, and the 1 litre liquid at about £15.86. The 250 g pack states NPK 8-1-5 and granules, with 5.0 from two reviews and no review text. It is not a UK trial. The 250 ml states NPK 4-1-7 and has no star line. The 1 litre states the same 4-1-7 and scores 3.9 from five reviews marked in Spain. Dilution is absent, so you follow the carton. Skip 5 litres, 10 litres and 20 kg for three pots.

Feed once

If you will not measure a cap every fortnight, Fertiligène Osmocote Max, 700 g at about £23.00, states one application. According to the manufacturer it is uncoated granules plus resin-coated granules, February to June, and 3 to 6 g per plant in a pot. The product data has no NPK. Most of the 129 reviews, at 4.7, were marked in France. Number of items 12 is unexplained, so do not assume twelve tubs. The one-year claim is the listing's words. Which? does not rank this tub or Cultivers. The fortnightly habit is on how to feed geraniums.
Cultivers Cultivers organic geranium and flowering plant fertiliser 250 g

Testsieger

Cultivers Cultivers organic geranium and flowering plant fertiliser 250 g
10.0/10about £11.62
View offer

Many baskets

The 5 litre liquid at about £35.29 is about £7.06 per litre of NPK 4-1-7. The 10 litre can at about £54.59 is about £5.46 per litre and 12.5 kg, with no star line. A coverage field of 10 has no unit. The pack is 10 litres. The 1 kg pack at about £15.53 is the better value on the 8-1-5 line, about four times the 250 g mass for roughly £4 more, and the form is not stated. Skip the 20 kg sack at about £60.42: the listing says 8-1-5 and one Spanish review says 8-7-5.

What not to crown

A missing star line means not rated here, not failed. Do not crown a pack certified organic. No listing names a UK certifier. Do not crown Osmocote as the NPK winner, and do not treat a Which? pelargonium trial as a score for these ASINs. Listing checks on 20 October 2026 were a few pence off the 19 October prices kept here: about £15.33 against £15.53 for 1 kg, and about £15.66 against £15.86 for 1 litre. Check the basket on the day. If you still do not know liquid or granules, use the geranium fertiliser buying guide. A border cranesbill is usually not a customer for any of these eight.

Common questions

Which pack for three pots?
The 250 g granules at about £11.62 or the 250 ml liquid at about £13.51. Use the granules when you want stated NPK 8-1-5 and the word granules on the listing. Use the 250 ml when you want stated NPK 4-1-7 and a bottle you can finish. The 1 litre liquid is the next step if 250 ml will run out, and it has a weaker star line of 3.9 from five reviews.
Which pack if I will only feed once?
The 700 g Osmocote Max tub at about £23.00, if you can accept no NPK in the product data and a February to June window. The printed pot dose is 3 to 6 g. It is the wrong shortcut if you wanted 4-1-7 or 8-1-5 written on the page you are reading.
Which pack for a lot of baskets?
The 5 litre 4-1-7 liquid at about £35.29 if you want a star line with the volume. The 10 litre can at about £54.59 if you will store 12.5 kg and you do not need reviews. The 20 kg sack is still a poor match, because the form is unstated and the NPK is disputed in the product data.
Is the highest star rating the winner?
No. Five stars from two reviews on the 250 g pack outranks 4.7 from 129 reviews only as an arithmetic score. The comparison marks that pack as the top pick on that score and says the sample is thin. Match the pack to the job, then read the stars as a sample size.
Why is the 20 kg rating the lowest?
The listing line is 3.2 from two reviews. The only review body does not praise the product, and it disputes the ratio, saying 8-7-5 where the listing says 8-1-5. That is a small, unhappy sample, not a nationwide poll. It is still a reason to avoid the sack for ordinary pots.
Is Osmocote organic?
The Osmocote product data does not make an organic claim. Cultivers titles do. Those Cultivers lines name no UK certifier, so organic on the title is not a scheme membership you can quote. Osmocote's resin-coated granules are a release claim, not an organic certificate.
Did prices move after 19 October 2026?
Listing checks on 20 October 2026 were a few pence away on some Cultivers sizes, and the Osmocote review count in one check was 130 against 129 here. This page keeps the 19 October shelf prices and the star lines from that capture. Check amazon.co.uk on the day you buy.

Related pages

Geranium fertiliser for pots and baskets

Geranium fertiliser

Geranium fertiliser buying guide: form, NPK and pack

How to feed geraniums in spring, summer and winter

Pelargonium or hardy geranium: which plant to feed

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the eight amazon.co.uk listings captured on 19 October 2026. Organic, vegan and pet-safety lines are listing claims. The one-year granule line is the listing's claim, not a laboratory result. French, Spanish and Belgian reviews are not British comments.

  1. RHS, How to grow pelargoniums (retrieved 19 October 2026)
  2. RHS, How to grow geraniums (retrieved 19 October 2026)
  3. RHS, How to feed plants (retrieved 19 October 2026)
  4. RHS, Fertiliser labels explained (retrieved 19 October 2026)
  5. GOV.UK, Manufacturing and marketing fertilisers (retrieved 19 October 2026)
  6. legislation.gov.uk, Regulation (EC) No 2003/2003 Title I (retrieved 19 October 2026)
  7. RHS, Storing and disposing of chemicals safely (retrieved 19 October 2026)
  8. amazon.co.uk listings for the eight compared packs (retrieved 19 October 2026)