Three numbers on the bag, and the fourth is the release

Lawn fertiliser, compared

A bag of lawn fertiliser states its composition because it has to: the NPK figures are a declared analysis, not a marketing claim, and they are the honest basis for comparing two bags. Nitrogen drives leaf growth and colour, phosphorus root establishment, potassium hardiness — which is why the autumn products in this corpus are potassium-heavy and the spring ones nitrogen-heavy, and why applying the wrong one in the wrong season is the commonest mistake on a lawn. The second pair of numbers is the weight and the coverage: 10 kg for 500 m², 6,25 kg for 250 m², 20 kg for a large lawn. Dividing one by the other gives the application rate the maker assumes, and that rate is what the spreader has to deliver. The release is the property that most changes the result and is least visible in the price. A quick-release fertiliser is soluble and works within days, with a real risk of scorching if it is applied unevenly or on dry grass. A coated, slow-release one meters itself out over weeks or months, costs more per kilogram and is far harder to get wrong. The form follows from it — granules for spreading, liquid concentrates for a sprayer or a hose feeder — and the application column says which tool the product expects. This site reports what the label publishes and never prescribes a dose, a date or a mixture: the bag carries instructions that are specific to the product, and they are the ones that apply. We compare weight, coverage, NPK, release, form and application.

Every part here, laid out figure by figure

1. 

   Plantura Bio-Herbstrasendünger 3 kg

   An EU-certified organic autumn feed — whose own listing gives two coverage figures a factor of two apart.

   Weight

   3 kg

   Coverage

   The title says 60 m²; the fifth feature line says 120 m². Both are published.

   NPK

   Not published; potassium named without a figure

   Release

   Organic, with a sustained supply stated over 3 months

   Form

   Low-dust organic granule

   Application

   Not stated directly — 50 g/m² or 25 g/m², depending on which coverage figure applies

   Amazon reference

   B07F8RJZVS (one reference across 3 Amazon marketplaces)

   EAN

   4024024170071

   • Cites two specific EU organic regulations by number, which nothing else here does
   • Animal-free organic ingredients, low dust and low odour
   • The title and the features disagree about coverage by a factor of two

   Best for: An autumn feed on a lawn used by pets, where organic certification matters

   Check price on Amazon
2. 

   SUPERGREEN.eu SGD0005000HD

   One of only two feeds here with a published analysis — and the only one that states its granule size.

   Weight

   5 kg

   Coverage

   250 m²

   NPK

   5-10-22 — the highest potassium figure published on this shelf

   Release

   Long-term action stated up to 100 days

   Form

   2 to 5 mm granule, stated dust-free

   Application

   20 g/m², from the published weight and area

   Amazon reference

   B0FR9ZZW87 (one reference across 1 Amazon marketplace)

   EAN

   9120136750073

   • A published NPK, which five of the seven feeds here do not give
   • The only granule size on this shelf — 2 to 5 mm, which is what a spreader is set for
   • Its potassium costs about twice as much per kilogram as the other analysed feed here

   Best for: An autumn feed where you want to know what you are buying and spread it accurately

   Check price on Amazon
3. 

   DÜNGEMEISTER 10 kg

   Ten kilograms at 20 grams a square metre — the cheapest square metre on this shelf, and no analysis.

   Weight

   10 kg

   Coverage

   Up to 500 m²

   NPK

   Not published; nitrogen, phosphorus and potassium each described by function without figures

   Release

   Long-term action claimed; no period published

   Form

   Mineral granule, stated optimised for spreaders and hand application

   Application

   20 g/m² for maintenance feeding, stated

   Amazon reference

   B0FN7WXBSJ (one reference across 1 Amazon marketplace)

   EAN

   4251862201937

   • About 0.056 € per square metre — joint cheapest on this shelf
   • A stated rate that matches its own weight and coverage exactly
   • No NPK figures, despite a whole feature line explaining N, P and K by function

   Best for: A 500 m² lawn fed in autumn, where cost per square metre decides

   Check price on Amazon
4. 

   turbogrün HERBST 5 kg

   A fine-granule mineral autumn feed with a named application window — September to December.

   Weight

   5 kg

   Coverage

   Not published; 20 g/m² gives about 250 m²

   NPK

   Not published; described as a balanced mixture of potassium and further nutrients

   Release

   Mineral, stated to act immediately after application

   Form

   Fine mineral granule

   Application

   20 g/m², stated

   Amazon reference

   B0B9C4FQXB (one reference across 2 Amazon marketplaces)

   EAN

   4260721110150

   • A named four-month application window, which three feeds here do not give
   • States plainly that it is a mineral feed, not organic
   • No coverage area published — it has to be derived from the rate

   Best for: A late autumn feed, applied by hand or with a small spreader

   Check price on Amazon
5. 

   Beckmann 67.144

   Three feature lines, a published analysis, and by a clear margin the cheapest potassium on this shelf.

   Weight

   20 kg

   Coverage

   Not published

   NPK

   6+3+13 — 2.6 kg of K₂O in the sack

   Release

   Not published

   Form

   Free-flowing crumb granule

   Application

   Not published

   Amazon reference

   B0CKVXLKFY (one reference across 1 Amazon marketplace)

   EAN

   4015505671446

   • About 11.86 € per kilogram of K₂O — roughly half the other analysed feed here
   • About 1.54 € per kilogram of product, the cheapest on this shelf
   • No application rate and no coverage — the cost per square metre cannot be worked out

   Best for: Anybody who knows their own application rate and wants potassium by the kilo

   Check price on Amazon
6. 

   Terra Domi Kali-Dünger 20 kg

   The highest application rate on this shelf at 40 to 45 g/m², and the only chloride-free claim.

   Weight

   20 kg

   Coverage

   Up to 500 m²

   NPK

   Not published

   Release

   Immediate and long-term action claimed

   Form

   Dust-free granule, stated chloride-free

   Application

   40 to 45 g/m², stated — the highest on this shelf

   Amazon reference

   B08JVJBPN6 (one reference across 1 Amazon marketplace)

   EAN

   4260400878036

   • Chloride-free, and the listing explains what that is for — it can also go on beds
   • Its rate, weight and coverage are all consistent at 40 g/m²
   • No NPK, on a bag whose name is its potassium

   Best for: A lawn and beds fed from the same sack, where chloride sensitivity matters

   Check price on Amazon
7. 

   TerraUno 20 kg

   The largest coverage here — 1,000 m² at 20 g/m² — and the only feed naming zeolite as a carrier.

   Weight

   20 kg

   Coverage

   1 000 m²

   NPK

   Not published; high potassium share claimed

   Release

   Immediate effect plus long action; zeolite stated to hold water and nutrients and reduce leaching

   Form

   Dust-free, low-odour granule with zeolite

   Application

   20 g/m², stated

   Amazon reference

   B0CJ9ZF4YP (one reference across 1 Amazon marketplace)

   EAN

   8720598703870

   • About 0.055 € per square metre — the cheapest square metre on this shelf
   • Zeolite named as a carrier, with a stated mechanism nothing else here offers
   • The dearest bag on this shelf in absolute terms, which is the figure people compare

   Best for: A large lawn fed in autumn, where cost per square metre and leaching both matter

   Check price on Amazon