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Yellow leaves and iron deficiency on youngest growth

Updated: October 2026

Yellow leaves and iron deficiency are not the same thing. Iron shortage usually shows on the youngest leaves, yellow between veins that stay green. Nitrogen, magnesium, manganese, drought, wet roots and chalk can yellow a plant as well. This page is the check before you order. It does not rank products. Dilution is on [how to apply iron fertiliser](/hub/fertiliser-soil-and-bark-mulch/iron-fertiliser/sub/iron-fertiliser-how-to-apply). The shelf is the [iron fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/iron-fertiliser). Peter F., the DIY and tools editor, updated this on 21 October 2026 from Royal Horticultural Society guidance and those listings. This is not a laboratory test. A qualifying purchase can earn a commission at no extra cost to you.

Yellow leaves and iron deficiency are not the same thing. Iron shortage usually shows on the youngest leaves, yellow between veins that stay green.

Our top picks

Doff Doff Sequestered Iron Plant Tonic

Best overall

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

Rank 2

Maxicrop Maxicrop Sequestered Iron 500 ml
8.9/10about £7.14
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Maxicrop Maxicrop Sequestered Iron 2 x 1 litre

Alternative

Maxicrop Maxicrop Sequestered Iron 2 x 1 litre
6.4/10about £17.00
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On this page
  1. 1.Where the yellow leaves are
  2. 2.Magnesium, manganese and nitrogen
  3. 3.Chalk, compost and tap water
  4. 4.What sequestered iron can do this season
  5. 5.When iron is the wrong long-term plan

Where the yellow leaves are

If the youngest leaves are yellow between green veins, that is the iron pattern the Royal Horticultural Society describes. In a severe case the leaf can lose almost all of its green. An AHDB note records the same idea on young petunia and primula leaves. Ericaceous plants may also brown at the edge. Drought and a pot that never dries can fade a canopy without that pattern. If you cannot see green veins on the newest leaf, do not assume iron.

Magnesium, manganese and nitrogen

Magnesium and manganese tend to start on older leaves, still yellow between the veins. Magnesium often shows on tomatoes, apples, roses and rhododendrons, and it can follow heavy potassium feeding on sandy soil. Nitrogen is a more general yellowing of older leaves, with poor vigour. Potassium trouble is often worse at the leaf edge. Overwatering can mimic an iron shortage because the roots cannot take iron up. Let the compost breathe before you add another feed.
Doff Doff Sequestered Iron Plant Tonic

Testsieger

Doff Doff Sequestered Iron Plant Tonic
7.3/10about £5.99
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Chalk, compost and tap water

On chalk, plants can fail to absorb iron even when the soil contains it. The RHS calls this lime-induced chlorosis. Sequestered iron can ease it for a time. It does not change the chalk, and this page gives no kilogram rates for acidifying free lime. Rhododendrons grow best around pH 4.5 to 6.0. As the pH approaches 7, a container is the reliable method. Prefer rainwater in a pot. A camellia wants ericaceous compost, with sequestered iron in mid-spring and early summer.

What sequestered iron can do this season

A short-term sequestered feed can green young leaves when the pattern really is iron, especially in a container. Examples, not a ranking, are the Maxicrop 500 ml listing, which states acid-loving plants, and the Doff powder. The two-bottle Maxicrop pack is more of the same liquid. Neither names EDTA, DTPA or EDDHA. Once you need iron, the form is on the iron fertiliser buying guide. This page does not print millilitres. A 5 litre concentrate is more than two pots need.

When iron is the wrong long-term plan

If you need sequestered iron every year, the RHS advice on chalk is to change the planting. Use lime-free compost in a container, or a plant that likes chalk. Avoid camellias and rhododendrons in a chalk border unless they are in containers. A large shrub that is dying back needs horticultural help, not a larger bottle. Iron salts are harmful if eaten. A lawn tub of ferrous sulphate is the wrong chemistry for this leaf pattern.

Common questions

Are yellow leaves always iron deficiency?
No. Iron is one pattern. The usual sign is young leaves turning yellow between veins that stay green. Older leaves fading, weak growth, a dry pot, or roots sitting in water can all look like a reason to buy iron. Check where the yellow sits first. A bottle will not correct a nitrogen shortage or a fortnight without water, however well reviewed the listing is.
Which leaves go yellow first if the plant is short of iron?
The youngest leaves. On the RHS description, iron shows at the growing tip, with yellow tissue and greener veins. AHDB notes the same on young petunia and primula leaves, which can become very pale while older leaves stay green until the shortage is severe. If the colour loss is halfway down an old shoot, look at magnesium and manganese before you assume iron. Photograph the new growth in daylight.
How does magnesium deficiency look different?
Magnesium tends to start on older leaves, still between the veins, often on tomatoes, fruit, roses and rhododendrons. It can follow a heavy potash feed on light soil, sometimes with reddish brown colour. Iron starts at the youngest leaves. If the old foliage is the problem and the tips are still green, magnesium is the more likely nutrient story. An iron drench is then the wrong tool.
Will iron fix drought, wet roots or a lack of nitrogen?
No. Drought and waterlogging stop the roots working, and nitrogen shortage is a general paling of older growth and poor vigour. Let a waterlogged pot dry to a sensible moisture, and water a dry one, before you decide the pattern is a nutrient. If the newest leaves are still a healthy green, iron is unlikely to be the missing piece. Feed after the water is right, not instead of it.
Can I keep a camellia in chalk if I feed iron every year?
The RHS treats a yearly need for sequestered iron as a sign to change the planting. On free chalk, put the camellia in a container of lime-free or ericaceous compost, or choose a plant that tolerates chalk. Short-term iron can ease lime-induced chlorosis for a season. It does not turn a chalk border into ericaceous soil, and a tub of fertiliser will not practically acidify that chalk.
When should I test the soil or get help instead?
When the pattern does not match young leaves with green veins, when a large shrub is dying back, or when you are thinking of digging chalk out of a border. A soil test is more honest than a third bottle. Get urgent medical help if a child or a pet has swallowed granules or concentrate.

Related pages

Lawn iron or shrub iron

Iron fertiliser

Best sequestered iron in the UK for a named garden job

Iron fertiliser buying guide: choose the right form

How to apply iron fertiliser from the bottle label

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)