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Iron fertiliser buying guide: choose the right form

Updated: October 2026

A camellia in a chalky border and a tired lawn beside the patio are not the same job. This iron fertiliser buying guide is the step before you choose a form: sequestered iron for a shrub, ferrous sulphate for a small lawn, or a product that should stay off the border. Prices sit on the [iron fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/iron-fertiliser). If the leaf pattern is still unclear, read [yellow leaves and iron deficiency](/hub/fertiliser-soil-and-bark-mulch/iron-fertiliser/sub/iron-fertiliser-yellow-leaves) first. Peter F., the DIY and tools editor, updated this on 21 October 2026 from those amazon.co.uk listings, not a laboratory test. A qualifying purchase can earn a commission at no extra cost to you.

A camellia in a chalky border and a tired lawn beside the patio are not the same job.

Our top picks

Doff Doff Sequestered Iron Plant Tonic

Best overall

Doff Doff Sequestered Iron Plant Tonic
7.3/10about £5.99
View offer
Maxicrop Maxicrop Sequestered Iron 500 ml

Rank 2

Maxicrop Maxicrop Sequestered Iron 500 ml
8.9/10about £7.14
View offer
Pro-Kleen Pro-Kleen Iron Sulphate 2.5 kg

Alternative

Pro-Kleen Pro-Kleen Iron Sulphate 2.5 kg
6.6/10about £16.95
View offer
On this page
  1. 1.Start with the job, not the brand
  2. 2.What the listings actually are
  3. 3.Pack size against the area you have
  4. 4.A rate and a chelate name you can read
  5. 5.What not to substitute

Start with the job, not the brand

Sequestered or chelated iron is the usual help for lime-induced chlorosis on a shrub or in a pot, because chalk can lock iron already in the soil. Ferrous sulphate greens turf quickly, then becomes hard for roots to use as the pH rises. Easy-Life Ferro is a tank supplement, and CANNA Mono FE has no garden dose. The RHS treats sequestered iron on chalk as short-term help. If you need it every year, use lime-free compost in a container. The lawn or shrub comparison takes that pair on its own.

What the listings actually are

Maxicrop 500 ml at about £7.14 names acid-loving plants and states Soil Association approval for organic growing. It is the top pick from Amazon stars, the review sample and the price, not a laboratory win. A second 500 ml at about £12.41 shares GTIN 05013762000176 and is 4.2 from nine reviews. Doff powder at about £5.99 is five 15 g packs, mixing field 1:0:0, brand field Plugplants.net. Pro-Kleen is 2.5 kg, up to 83 m². Sunshine at about £29.99 and Substral disagree with their own size lines.
Doff Doff Sequestered Iron Plant Tonic

Testsieger

Doff Doff Sequestered Iron Plant Tonic
7.3/10about £5.99
View offer

Pack size against the area you have

Under £10 is a small shrub treatment, not a lawn programme. Reviewers call 500 ml very small, and one person used a whole Maxicrop bottle in one round. Two 1 litre bottles at about £17.00 are the volume step, and their reviews repeat the 500 ml sample. Doff’s five sachets suit a couple of shrubs if the carton has a rate. Pro-Kleen’s 2.5 kg matches a small lawn at up to 83 m². Five litres at 1:400 is a lot for two camellias.

A rate and a chelate name you can read

Maxicrop’s 500 ml field says 1. Doff and the twin pack say 1:0:0. Easy-Life’s bullet says 5 ml per 100 litres, while the field says 1:20. The rate has to come from the label or a named sheet. UK fertiliser marking expects a UK FERTILISER mark, iron as Fe, and chelated by when the iron is chelated. None of these garden listings names EDTA, DTPA or EDDHA. As a rule of thumb, not UK law, EDTA holds to roughly pH 6, DTPA weakens by about pH 8, and EDDHA still works past pH 9.

What not to substitute

Ferrous sulphate on a camellia is not a saving against a shrub bottle at about £7.14. A sequestered bottle over a whole lawn is not a 2.5 kg tub with a coverage figure. Aquarium iron and CANNA’s mono-iron stay in their systems. Unless it is authorised, the RHS says ferrous sulphate sold only as a fertiliser should not be used to control moss. The best sequestered iron page names one listing for each job.

Common questions

Which iron fertiliser should I buy if the new leaves are yellow?
If the youngest leaves are yellow between green veins, the usual garden form is sequestered or chelated iron, not a lawn tub of ferrous sulphate. On this shelf that points towards Maxicrop's 500 ml listing or the Doff powder, after you have checked the pattern. Yellowing of older leaves, or a dry or waterlogged plant, is a different problem.
Is lawn ferrous sulphate the same product as sequestered iron?
No. Both supply iron, and then they part company. Ferrous sulphate is the fast lawn colour on this shelf, and it can stain stone. Sequestered iron is the short-term help for acid-loving shrubs on chalk or in the wrong compost. The Pro-Kleen tub on a rhododendron, bought because it was cheaper, is the swap to avoid.
Can I pour aquarium iron or a hydroponic iron on the border?
Easy-Life Ferro is an aquarium supplement, with a bullet of 5 ml per 100 litres. CANNA Mono FE has no numeric garden dose and no named agent. Neither gives a shrub drench or a lawn coverage. Keep that bottle in the system it was mixed for.
What should chelated by mean on the label?
It should name the agent, typically EDTA, DTPA or EDDHA, so you can compare a pH band. A bottle that only says chelated or sequestered has not given you that name. None of the garden listings here prints those three agents. If your carton names the agent, use that wording.
Is a 5 litre concentrate too much for two camellias?
For two camellias, yes. The 5 litre Sunshine listing is a 1:400 seaweed concentrate with unnamed chelated iron at about £29.99. A 500 ml Maxicrop bottle, or five small sachets, matches a couple of shrubs more closely. You still need a dilution from the label.
Does a Soil Association claim say anything about pets?
It says the listing states approval for organic growing. It does not say the product is harmless if a dog or a child eats it. Iron salts are harmful if swallowed. Keep pets off a treated lawn while it is wet, and store concentrate out of reach. If someone has swallowed it, get urgent medical help.

Related pages

Best sequestered iron for a named job

Iron fertiliser

How to apply iron fertiliser from the bottle label

Iron sulphate or sequestered iron for a lawn or shrub

Yellow leaves and iron deficiency on youngest growth

Sources

Public UK and maker sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the ten amazon.co.uk listings. A Soil Association line is an organic-growing claim, not a pet study. The Maxicrop 2% and 45 ml figures are from the professional sheet, not from the amazon mixing field. Chelate pH bands from a US extension summary are not UK law.

  1. RHS, nutrient deficiencies (retrieved October 2026)
  2. RHS, chalky soils (retrieved October 2026)
  3. RHS, moss in lawns (retrieved October 2026)
  4. GOV.UK, manufacturing and marketing fertilisers (retrieved October 2026)
  5. legislation.gov.uk, Regulation (EC) No 2003/2003, Article 9 (retrieved October 2026)
  6. HSE, garden and home pesticides (retrieved October 2026)
  7. Maxicrop professional iron sheet (retrieved October 2026)
  8. Easy-Life Ferro (retrieved October 2026)