The best iron fertilisers, compared.
Top pick: Doff Sequestered Iron Plant Tonic Best value: Doff Sequestered Iron Plant Tonic – Lowest shelf price for a sequestered-iron form, about £5.99, if you read the carton for a real rate. Updated October 2026.
Iron fertiliser supplies iron so leaves can make chlorophyll. On amazon.co.uk the shelf mixes sequestered or chelated iron for shrubs and pots, ferrous sulphate for lawns, seaweed concentrate with added iron, and bottles for aquariums or hydroponics. You buy it because new leaves are yellow between green veins, a lawn looks tired, or an acid-loving shrub sits in chalk or hard tap water. A suitable product matches the job, the iron form, the pack size and a dilution you can read. Sequestered iron is the short-term remedy for lime-induced chlorosis on shrubs. Ferrous sulphate is the usual lawn iron, and it can stain stone. An aquarium bottle and a hydroponic mono-iron belong in those systems, not on a border. If the listing only says chelated or sequestered and does not name the agent, you cannot match it to soil pH from the bullets. Which form fits which job is set out in the [iron fertiliser buying guide](/hub/fertiliser-soil-and-bark-mulch/iron-fertiliser/sub/iron-fertiliser-buying-guide). A fertiliser is not an authorised moss killer. Keep pets off a treated area while it is wet, and follow the label.
Iron fertiliser supplies iron so leaves can make chlorophyll.
36 products checked · 62 hrs invested · +21,400 readers
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Personal buying guide
Question 1 of 2
Where are the yellow leaves?
The Doff sequestered iron listing is five 15 g powder packs at about £5.99, the lowest shelf price in this comparison. Across 22 amazon.co.uk ratings it sits at 4.7, though only four United Kingdom review texts were saved, so the sample is thin. Those reviews describe greener laurels, a blueberry that stopped yellowing, and a camellia that looked healthier after one treatment, and none of them states the dilution used. The mixing field prints 1:0:0, which is not a rate you can follow from the listing. The brand line says Plugplants.net while the title says Doff, and the item weight of 15 g does not match the 75 gram unit count for five packs. There is no stain, pet or moss line on the listing, and the target-species field simply says all plants. That price is why it is the best value here, as long as you read a real label before you mix it.
Pros
Cons
Best for: You want a small sequestered-iron powder for a few shrubs and you will check the carton for a real rate.
Less suitable: You need a printed watering-can dilution on the amazon page, or a lawn granule with a coverage figure.
Specifications
Common questions
What form is this iron feed?
The item form is powder. The title says five 15 g packs. The unit count is 75 gram and the item weight is 15 g, so those two size lines do not match.
Does the listing give a dilution?
The mixing-ratio field says 1:0:0. That is not a usable dilution. Read the carton before you mix it.
Which plants does the listing name?
The target-species field says all plants. The title calls it a sequestered iron plant tonic. The brand field says Plugplants.net.
Sunshine Renewables lists a seaweed feed with added chelated iron at about £18.99, with 1:400 on the title and the mixing field, and 4.7 from nine reviews. The pack size does not agree with itself: the title and liquid volume say 2.5 litres, the unit count is 10,000 ml, and a bullet says Generous 10L. Only three UK texts were saved, and the same three texts and the same best-seller rank appear on the 5 litre listing, so this is not a separate trial of a 2.5 litre bottle. Those texts say it works, arrived quickly, and greened plants through a sprayer almost straight away. The title says organic liquid plant feed, but there is no Soil Association line, and the chelating agent is not named. The plant list runs from lawns to hydroponics. Until the carton confirms one volume, this is the listing to leave on the shelf.
Pros
Cons
Best for: You would only consider it after the seller confirms whether the bottle is 2.5 litres or 10 litres.
Less suitable: You need a known volume for two camellias, or a listing whose size fields agree.
Specifications
Common questions
How big is the bottle?
The title and liquid volume say 2.5 litres. The unit count is 10,000 millilitres and a bullet says Generous 10L. Do not treat one of those as confirmed.
What dilution is printed?
The title and the mixing-ratio field both say 1:400.
Are the nine reviews only for this size?
The three saved UK texts and the best-seller rank match the 5 litre listing. Do not read them as a separate trial.
The 5 litre Sunshine Renewables seaweed with chelated iron is about £29.99, and the title, unit count and liquid volume all say 5 litres, unlike the conflicting smaller listing. The rate on the page is 1:400. The star line is again 4.7 from nine reviews, with the same three UK texts and the same rank as the other Sunshine listing, so you should not read that as a separate test of this bottle. The texts mention greener growth through a sprayer, described as almost immediate, plus fast delivery. The chelating agent is not named, and the organic wording is in the title without a Soil Association line. Bullets claim a wide list that includes lawns, shrubs, houseplants, vegetables and hydroponics. At this price and volume it is a large seaweed concentrate, not the watering-can pick for two camellias.
Pros
Cons
Best for: You want a large 1:400 seaweed concentrate with added iron and you have checked that the carton is 5 litres.
Less suitable: You are feeding two camellias, or you want a shrub tonic with a large UK review sample.
Specifications
Common questions
What size is printed?
Title, unit count and liquid volume all say 5 litres. A bullet says Generous 5L.
What dilution is printed?
The title and the mixing-ratio field say 1:400.
Are the reviews unique to this bottle?
The three saved UK texts and the best-seller rank match the other Sunshine listing. Do not count them twice.
Easy Life Ferro is a 500 ml aquarium iron at about £10.39, model FE1002. The listing is 4.6 from 1,776 reviews, but only 11 of the first 50 saved texts are from the United Kingdom, so that headline count is not a British garden sample. A bullet says 5 ml per 100 litres, while the mixing field says 1:20, and those two figures do not match. UK reviews describe deep green tank plants, red plants kept on a weekly dose, a large lily in the tank, and fish that were unaffected in one report. Water turning cloudy for a couple of hours is a repeated comment: one reviewer calls it normal and another calls it a fault. One review says the bottle was expired. The bullets do not name a lawn or shrub rate. This belongs in a planted tank, not on a camellia or a lawn.
Pros
Cons
Best for: You dose a planted aquarium and you will follow the 5 ml per 100 litres bullet rather than the 1:20 field.
Less suitable: You are treating a lawn, a shrub border or a pot on the patio.
Specifications
Common questions
What dose does the listing print?
A bullet says 5 ml per 100 litres. The mixing-ratio field says 1:20. Those two figures do not match. Easy-Life's UK page says 5 ml per 100 litres weekly.
Is this a lawn or shrub feed?
The saved UK reviews describe tank plants and fish. The bullets do not name a lawn or a shrub rate.
Are the 1,776 reviews all from the UK?
The listing count is 1,776. Only 11 of the first 50 saved reviews are from the United Kingdom.
Maxicrop's 500 ml sequestered iron with seaweed is about £7.14 and is aimed at acid-loving plants. The amazon.co.uk line is 4.6 from 1,174 reviews, and all 50 saved texts are from the United Kingdom, which is the strongest British sample among the shrub bottles. Reviewers describe faster greening on camellias and a red-leaved witch hazel, and they use it on azaleas and rhododendrons in alkaline soil, plus citrus, blueberry, fatsia, laurel and pyracantha. A bullet states Soil Association approval for organic growing. The mixing field is only 1, so the page does not tell you millilitres per watering can, and a customer question about pets goes unanswered. Several people call 500 ml very small, one used the whole bottle in one round, and the seal needed a sharp tool because there was no pull tab. One reviewer saw no change and blamed the compost, and a long-term user mentioned salt traces and a very low pH. It is the top pick for a watering-can treatment of ericaceous shrubs, not a lawn-wide green-up.
Pros
Cons
Best for: You are feeding camellias, azaleas, rhododendrons or similar acid-loving plants from a watering can.
Less suitable: You want a confirmed millilitre rate on the amazon page, a whole-lawn treatment, or enough volume for many shrubs at once.
Specifications
Common questions
What plants does the listing name?
The target-species field says acid-loving plants. The highlight also says ericaceous and acid-loving plants.
Is a dilution printed on the listing?
The mixing-ratio field says 1. The bullets do not give millilitres per watering can. A professional sheet states 45 ml in 9 litres. That rate is not in the amazon mixing field.
Does the listing say it is safe for pets?
A customer question asks about pets. The bullets do not answer it. They do say the Soil Association approves it for organic growing.
This Maxicrop pack is two 1 litre bottles of sequestered iron with seaweed at about £17.00, for acid-loving plants, with a Soil Association organic-growing claim in the bullets. The star line is 4.6 from 1,174, the same figure as the 500 ml listing, and the saved UK texts are the same set, including the complaint that the bottle is very small, which describes 500 ml rather than this twin pack. Do not treat that count as a second, independent sample. The mixing field is 1:0:0, so there is still no dilution on the amazon page, and a bullet says the information applies to each unit. On the listing it ranks 13 in Flower Fertilisers. It makes sense when you already know 500 ml will not cover the shrubs you are treating, not because the reviews prove a different product.
Pros
Cons
Best for: You already want Maxicrop sequestered iron and you know 500 ml is too little for the shrubs you are feeding.
Less suitable: You are judging it on a fresh review sample, or you only have one or two pots.
Specifications
Common questions
How much liquid is in the pack?
Number of packs is 2. Unit count is 2,000 millilitres. Liquid volume is 2 litres. Item weight is 2 kg.
Are the 1,174 reviews for this twin pack?
The saved UK texts match the 500 ml listing, including a review that the bottle is very small. Do not count them as a second sample.
Is a dilution printed?
The mixing-ratio field says 1:0:0. The bullets do not give millilitres per can.
Substral 7391 is listed at about £15.35 as a liquid iron, with lawns and turf named in the fields and 4.6 from 848 reviews. None of the first 50 saved reviews is from the United Kingdom. The praise sits in German texts about kiwi, citrus and a swamp oak, while an Italian review reports no result on a lemon after two doses and a German review says some roses made no new leaves. Pack size cannot be confirmed: the unit count is 250 ml, the liquid volume is 2,000 ml and the item weight is 320 g. There is no mixing-ratio field, and a pet question on the page is unanswered. One German review mentions moving bark mulch aside before use. The star line looks strong, but you cannot tell which bottle size you would receive, and the saved experience is not a UK lawn trial.
Pros
Cons
Best for: You only consider it after the seller confirms one pack size, and you accept a non-UK review sample.
Less suitable: You want a UK-reviewed lawn granule or a shrub bottle with one consistent volume.
Specifications
Common questions
How big is the bottle?
The listing conflicts. Unit count is 250 millilitres, liquid volume is 2,000 millilitres, and item weight is 320 g. This page does not confirm one size.
Are the reviews from the UK?
The listing count is 848. None of the first 50 saved reviews is from the United Kingdom.
Does the listing name a lawn?
Coverage says lawns and turf grasses. Target species says lawn grass. The saved reviews mostly describe other plants.
CANNA Mono FE is a 1 litre iron chelate at about £15.00, sold through Hydrogarden, with 4.4 from 82 reviews and eight UK texts in the saved sample. Bullets say the iron can be absorbed directly, mixed with all fertilisers, and is stable with each pH, but they do not name EDTA, DTPA or EDDHA and they give no millilitres for a garden watering can. A reviewer who already uses CANNA found it easy and without odour, and another dosed a magnolia lightly and expected the large bottle to last. One 30-year-old rose showed no change in yellow leaves, and the magnolia reviewer could not tell whether those leaves would be less yellow. The lid leaks when the bottle is touched, and that reviewer says the leaked liquid stains, though it is usually easy to remove. A listing question asks if it is organic; the bullets do not say yes. Treat it as a single-element iron for a feed programme you already run, not as a labelled shrub drench.
Pros
Cons
Best for: You already run a CANNA feed and want a single-element iron you can add in small amounts.
Less suitable: You need a named shrub dilution, a Soil Association line, or a lawn granule.
Specifications
Common questions
Does the listing name the chelate?
The title says iron chelate. EDTA, DTPA and EDDHA are not named, so you cannot match chelate strength to soil pH from the bullets.
Is there a garden dose?
No. The mixing field says it can be mixed with all fertilisers. There is no millilitre rate.
What size is printed?
Liquid volume is 1 litre. Item weight is 1.1 kg. Unit count is 1.0 count.
This second Maxicrop 500 ml listing is about £12.41 and names azaleas, camellias, rhododendrons and heathers. It shares GTIN 05013762000176 with the about £7.14 Maxicrop bottle, and the manufacturer field says Seezon UK. The star line is 4.2 from nine reviews, with two saved UK texts: one calls it a vital boost for ericaceous plants and another says it brings fruit crops on fast. Neither text describes a dose or a failure. There is no mixing-ratio field, and the coverage field is the number 2, which is not an area. The title adds a postage claim rather than a product feature. At a higher price than the better-reviewed 500 ml listing of the same GTIN, it is a weaker way to buy the same kind of shrub tonic.
Pros
Cons
Best for: You specifically want the Seezon UK listing that names those four ericaceous plants and you accept a thin review sample.
Less suitable: You can buy the about £7.14 Maxicrop listing, which carries the larger UK review set.
Specifications
Common questions
Which plants are named?
The target-species field lists azaleas, camellias, rhododendrons and heathers.
Is a dilution given?
There is no mixing-ratio field on this listing. The coverage field is the number 2, which is not an area.
Is this the same code as the cheaper Maxicrop bottle?
The GTIN is 05013762000176, the same number as the about £7.14 listing. The manufacturer field here is Seezon UK.
Pro-Kleen iron sulphate spreader granules are 2.5 kg at about £16.95, ready to use, with coverage of up to 83 m² on the amazon.co.uk listing. The listing is 4.1 from 76 reviews, and 20 UK texts were saved. Reviewers say the fine granules run in a manual spreader and the grass looks more vibrant, and several report moss turning black or clearing. One person followed the instructions, saw no blackening, and called it a waste of money. The iron smell is strong, reviewers say wear gloves, and one found the spreader flow hard to control. The listing warns that it may stain hard outdoor surfaces, and it says not to use it if there is a frost risk, with a claim of one application for up to three months. A reviewer quotes about 100 m² while the listing says 83 m². The listing gives no grammes per square metre, and one saved review is about a saw, which does not match this tub. It is the lawn green-up in this set, not a shrub tonic and not an authorised moss killer.
Pros
Cons
Best for: You have a small lawn you can keep off paving, and you will follow the tub rather than a soluble recipe from a blog.
Less suitable: You are treating a camellia, working beside stone you cannot keep clear, or expecting a licensed moss killer.
Specifications
Common questions
Do you mix it with water?
The title says no mixing and ready to use. It is a granule for the lawn, not a watering-can concentrate.
Will it stain the patio?
The bullets say the product may stain hard outdoor surfaces. They also say magnesium prevents staining on the lawn. Keep it off paving.
Is it labelled as a moss killer?
The title calls it a grass greening fertiliser. Active ingredients are sulphate and iron. No MAPP number is on the listing. Reviews disagree about moss. Fertiliser-only ferrous sulphate is not a moss killer.
Ten amazon.co.uk listings were scored from the stored pages and the UK review notes already on file. There is no laboratory test. A dilution, a coverage figure or a Soil Association line is the seller's claim. Where two figures on one listing disagree, both stay and the clash is a deduction. A shared review count is not scored twice. The highest score is the top pick. The best value is the lowest price for a sequestered-iron form you can use on garden plants, and it does not also take the top score. The weights below sum to 100.
Amazon evidence
25%Star rating on amazon.co.uk, then the size of that listing's review file, then whether the saved texts are from the United Kingdom. Maxicrop 500 ml at 4.6 from 1,174, with 50 saved UK texts, takes more of this block than a 4.7 from nine reviews that are shared with another size. A German or Italian sample is a deduction.
Job and iron form
30%The stated job has to be a readable garden, lawn or aquarium use, and the iron form has to match it. Sequestered iron for shrubs, ferrous sulphate for a lawn, and an aquarium or hydroponic bottle stay in those systems. A missing chelate name, where the listing only says chelated or sequestered, is a deduction.
Pack and rate
30%Pack size and the mixing field have to be followable. A field of 1 or 1:0:0, two size lines that disagree, or a 1:20 field that contradicts a 5 ml bullet, is a deduction. A coverage figure such as up to 83 m² scores here. A shared review file does not repair a missing rate.
Price
15%Shelf price in GBP on the saved amazon.co.uk listing. The lowest price for a sequestered-iron form you can use on garden plants is the best value. It does not also take the highest score. A dearer bottle of the same GTIN is a deduction.
Match the iron form to the job before you match the star line. A shrub tonic, a lawn granule, an aquarium bottle and a hydroponic mono-iron are not one list. Prices below are amazon.co.uk shelf prices. This is not a laboratory test.
Iron fertiliser supplies iron (Fe) so leaves can make chlorophyll. On amazon.co.uk this shelf mixes sequestered iron for shrubs and pots, ferrous sulphate for lawns, seaweed concentrate with added chelated iron, and specialist bottles for aquariums or hydroponics. You usually arrive because new leaves are yellow between green veins, a lawn looks tired, or an acid-loving shrub sits in chalk or hard tap water.
Ferrous sulphate is the lawn form. Sequestered iron is the shrub form. A 500 ml bottle will not feed a whole lawn, and a lawn tub will not correct lime-induced chlorosis on an acid-loving shrub.
Moss may blacken. That is not an HSE authorisation. Fertiliser-only ferrous sulphate is not a moss killer. A lawn-sand pesticide needs a MAPP authorisation.
Fields of 1 and 1:0:0 are not dilutions. On the aquarium listing, 1:20 does not match 5 ml per 100 litres. Use the bottle label. Do not print a professional sheet rate as if it were on the amazon page.
Name the job first. Sequestered or chelated iron is the usual remedy for lime-induced chlorosis on shrubs and in pots. Ferrous sulphate is the usual lawn iron. Aquarium iron and a hydroponic mono-iron stay in those systems. The RHS describes iron deficiency as yellowing between the veins on the youngest leaves. Other nutrients, drought and wet roots yellow plants too. On chalk, iron is short-term, and lime-free compost is the longer fix.
A 500 ml concentrate is a watering-can product. A 2.5 kg granule tub is a lawn product. A 5 litre 1:400 concentrate is a lot of feed for two camellias. Use the bottle label. Mixing fields on these listings include 1, 1:0:0 and 1:20. The 1:20 field does not match a bullet of 5 ml per 100 litres. A professional Maxicrop sheet states 2% water-soluble iron and 45 ml in 9 litres. That rate is not in the amazon mixing field. Where two size lines disagree, do not pick one and call it confirmed.
Three typical situations, each with a recommendation from this comparison.
New leaves on a camellia, azalea or rhododendron are yellow between green veins, and the soil or the tap water is hard. Maxicrop Sequestered Iron 500 ml is the top pick at about £7.14, with 4.6 from 1,174 reviews and a Soil Association line for organic growing. The mixing field is only 1, so take the millilitres from the carton. It is not a lawn tub.
The grass looks tired and you can keep granules off stone. Pro-Kleen Iron Sulphate 2.5 kg is about £16.95, ready to use, with coverage of up to 83 m². The listing says it may stain hard surfaces. It is 4.1 from 76 reviews. It is not an authorised moss killer, and it is the wrong product for a yellow camellia.
The yellowing is in the tank, not in the border. Easy-Life Ferro 500 ml is about £10.39. A bullet says 5 ml per 100 litres. The mixing field says 1:20, and those figures do not match. The listing is 4.6 from 1,776 reviews, with 11 UK texts in the first 50. Do not pour it on a shrub.
The top pick for acid-loving shrubs is Maxicrop Sequestered Iron 500 ml at about £7.14. It has the highest score: the listing names acid-loving plants and seaweed, states Soil Association approval for organic growing, and shows 4.6 from 1,174 reviews, with the saved texts from the United Kingdom. The mixing field is only 1, so the page does not give millilitres per watering can. The best value is Doff Sequestered Iron Plant Tonic at about £5.99, five 15 g powder packs, the lowest price for a sequestered-iron form in this set. The mixing field is 1:0:0, the brand field says Plugplants.net, and only four UK review texts were saved against a count of 22. Pro-Kleen is the lawn granule, up to 83 m², and it may stain hard surfaces. Easy-Life Ferro is aquarium iron. None of these scores is a laboratory test.
Doff Sequestered Iron Plant Tonic
Lowest shelf price for a sequestered-iron form, about £5.99, if you read the carton for a real rate.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
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.
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 page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are from the listings. This is not a laboratory test.
