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What a nitrogen fertiliser label must show before you buy

Updated: October 2026

A tub that says nitrogen can still hide the percentage, the dose, and the job. A nitrogen fertiliser label has to show those three before the price means anything. The [nitrogen fertiliser comparison](/hub/fertiliser-soil-and-bark-mulch/nitrogen-fertiliser) tables the saved amazon.co.uk listings. This page is the check you run first. Prices are the 19 October 2026 snapshot. This page is from Peter F., the DIY and tools editor. The listings were read alongside the Royal Horticultural Society and GOV.UK. This is not a lab test. A qualifying purchase can earn a commission at no extra cost to you.

A tub that says nitrogen can still hide the percentage, the dose, and the job. A nitrogen fertiliser label has to show those three before the price means anything.

Our top picks

Hesi Hesi TNT Complex, 500 ml

Best overall

Hesi Hesi TNT Complex, 500 ml
6.8/10about £14.28
View offer
Bottos Bottos Sprint N, 2 kg

Best value

Bottos Bottos Sprint N, 2 kg
8.4/10about £13.87
View offer
Bottos Bottos Sprint N, 4 kg kit

Rank 3

Bottos Bottos Sprint N, 4 kg kit
8.6/10about £29.01
View offer
On this page
  1. 1.What you check before the price
  2. 2.How to read the NPK line
  3. 3.What these listings actually print
  4. 4.Ammonium nitrate, and what these packs do not say
  5. 5.What you can decide from the label

What you check before the price

Start with the plant. A lawn you want denser in spring is a different job from leafy vegetables, herbs, or a vegetative bottle. A 27-0-14 turf granule is the wrong tool for a tomato. A 3-2-3 grow liquid is the wrong tool for an 80 square metre lawn. Then read the nitrogen figure on the tub you will receive, and a dose with units. The RHS says a spring lawn fertiliser is high in nitrogen and should not be pushed beyond August.

How to read the NPK line

The first figure is nitrogen as the element. Phosphorus and potassium are often shown as oxides, P2O5 and K2O, with the element in brackets. Where bare numbers are used, the Fertilisers Regulations 1991, Schedule 2, put them in that order. The conversion factors there are P2O5 × 0.436 and K2O × 0.83. A straight high-nitrogen example from the RHS is sulphate of ammonia at 21-0-0 plus sulphur. Do not treat 21-0-0 as a stand-in for a compound such as 27-0-14.
Hesi Hesi TNT Complex, 500 ml

Testsieger

Hesi Hesi TNT Complex, 500 ml
6.8/10about £14.28
View offer

What these listings actually print

Bottos Sprint N, 2 kg, was £13.87, with a title of 27-5-15 and bullets of 27-0-14. The 4 kg pack, at £29.01, agrees on 27-0-14. Coverage is still not the sentence apply 25 g per square metre. Measuring is on how to use nitrogen fertiliser. VegAzoto names nitrogen and potassium with no percentages, and the 5 litre title says 5 kg while the unit count is 5,000 ml. UK Grow and the Vitax multipack print neither a percentage nor a dilution, and the Vitax picture may differ after a rebrand.

Ammonium nitrate, and what these packs do not say

The licence test is nitrogen from ammonium nitrate, not total nitrogen on a lawn bag. Solid ammonium nitrate above 28 per cent nitrogen, in consignments of 500 kg or more, needs a detonation-resistance certificate. None of these listings name ammonium nitrate. Urea, coated urea and a plant-origin liquid are outside that public-licence line. A house lawn is outside the farmland closed period. A pitch goes to a turf adviser. The lawn months are on nitrogen fertiliser for lawns.

What you can decide from the label

Pass a listing when the job matches, a nitrogen figure is printed, and a dose has units. In this set that is the 4 kg Bottos granule for a lawn in the spring window, because model and bullets agree on 27-0-14. The 2 kg pack passes only after you see which NPK is on the tub. Vitax and UK Grow only say high nitrogen or Nitrogen Plus, so ask the seller or leave them. Liquid versus granules is a separate choice, on liquid or granular nitrogen fertiliser.

Common questions

What has to be on a nitrogen fertiliser label before the price matters?
You need the job, the nitrogen figure, and a dose with units. Grams per square metre suit granules. Millilitres per litre suit a liquid. A lawn also needs a season, because a spring analysis is not an autumn feed. A listing that only says high nitrogen has not given you a specification, however many stars sit under the title.
Why can a balanced NPK still be nitrogen-weighted?
Oxide figures and element figures are different units. The RHS example of Growmore at 7:7:7 works out at about 7% nitrogen, 3.1% phosphorus and 5.8% potassium once phosphorus and potassium are elements. Compare like with like, or a lawn compound and a balanced feed will look more similar than they are.
What if the title and the bullets print different NPK figures?
Treat them as a clash. On Bottos Sprint N 2 kg the title prints 27-5-15 and the bullets print 27-0-14. The 4 kg listing's model and bullets both print 27-0-14. Ask which figure is on the tub, or buy the listing that does not contradict itself. Do not invent a midpoint between the two lines.
Is a plant-origin liquid with no percentages a complete label?
No. VegAzoto names nitrogen and potassium and prints 300–500 g per 100 litres, which is a dose in grams, not a percentage. Natural origin is not an organic certification. You can weigh that gram line. You cannot say how much nitrogen the plant received.
When does ammonium nitrate need a licence, and do these packs contain it?
In Great Britain, ammonium nitrate at or above 16 per cent nitrogen is a regulated precursor for public sale, and the buyer needs an EPP licence. Northern Ireland does not offer the public that licence. These listings do not name ammonium nitrate, so they do not show that these packs need that licence. Total nitrogen on a lawn granule is not the same test.
Is 2 kg covers 80 square metres the same as a gram rate?
It is a coverage claim. Dividing 2,000 g by 80 square metres implies 25 g per square metre, and 4 kg for 160 square metres implies the same sum. A review that says 30–35 g is a different figure. Do not merge them, and do not spread by the handful because the arithmetic looks tidy.
Should star ratings outrank a missing dose?
No. UK Grow is £10.99 with 3.9 from three reviews and no dose. Vitax is £59.41 with no review line and no dilution. The large Bottos sample is useful only after you accept the analysis, and those texts are tagged Italy. Stars do not fill a blank rate.

Related pages

Best nitrogen fertiliser

Nitrogen fertiliser

Nitrogen fertiliser for lawns, and the months that matter

How to use nitrogen fertiliser without guessing the rate

Liquid or granular nitrogen fertiliser for the job

Sources

Public UK sources from the research digest, used for this page in October 2026. Prices, stars and review counts are from the seven amazon.co.uk listings captured on 19 October 2026. A 60–90 day release claim was not measured. These listings do not name ammonium nitrate. A domestic lawn is outside the English nitrate vulnerable zone closed period.

  1. RHS, Lawn care in spring and summer (retrieved 19 October 2026)
  2. RHS, Fertiliser labels explained (retrieved 19 October 2026)
  3. RHS, Fertilisers: types and uses (retrieved 19 October 2026)
  4. RHS, Lawns: dead patches (retrieved 19 October 2026)
  5. GOV.UK, Supplying explosives precursors and poisons (retrieved 19 October 2026)
  6. GOV.UK, Using nitrogen fertilisers in nitrate vulnerable zones (retrieved 19 October 2026)
  7. GOV.UK, Rules for farmers and land managers to prevent water pollution (retrieved 19 October 2026)
  8. BBC Gardeners' World, Understanding and using NPK fertiliser (retrieved 19 October 2026)