Read the bag, because the rate differs by a factor of four across this shelf. A concentrated slow-release product and a bulky organic one are not applied at the same quantity, and the coverage claim on the front assumes you use the right one.
Why no single answer covers it
Lawn feeds vary enormously in concentration. A compact mineral granule at a high NPK is spread thinly; an organic or a sand-carried product at a low analysis is spread thickly. Both are correct at their own rate, and each bag states its own.
The figure to look for is grams per square metre, on the back. The square metres on the front is that rate multiplied by the bag, and it is only true if you apply at the rate.
Calibration, which is the real skill
A spreader’s setting numbers are not a unit. The same setting on the same machine passes different quantities of two different products, because granule size and density differ.
The check takes ten minutes. Weigh out the quantity the bag specifies for a measured area — say ten square metres. Mark the area. Spread at your best guess of the setting and see whether you finish the measured quantity in the measured area. Adjust and repeat.
Do this once per product and note it on the bag with a marker. It is the difference between an even lawn and a striped one.
Two passes at right angles
Halve the quantity, do the lawn in one direction, then do it again across. Any unevenness in the pattern is averaged out rather than repeated, and the overlap errors cancel instead of compounding.
The precaution
Sweep hard surfaces afterwards and before watering in, especially with anything iron-based. And keep the hopper shut while crossing paving.
How this site handles it
Fertiliser pages here print the stated rate in grams per square metre and the coverage in square metres as the maker gives them, alongside the NPK. Spreader pages print the working width and say whether the machine offers a calibration or only numbered settings, because that is what decides whether the rate on the bag can actually be applied.
Wherever this page and the maker’s own documentation disagree, the documentation wins. Every cutting width, cutting height, stated area, pack capacity, flow rate, head, sound level and application rate on this page comes from the maker’s own published figures, with the unit as printed and the source named. None of it is measured here, and no figure is converted into another convention, because a converted number is a different number. And the document this page hands back: the dose, the precautions and what a product may be applied to are on its label. That label is a legal text for a regulated product, and paraphrasing it would be rewriting it. This page reports the coverage and the analysis as the maker prints them, and points at the label for everything else.
The questions that keep coming in
Can I just judge it by eye?
On a very small lawn, with care, in two passes at right angles. On anything larger the eye produces stripes, and fertiliser stripes are visible for months because the difference is in colour and growth rate rather than in the granules.
Does more feed give a greener lawn?
Up to the stated rate. Beyond it the excess is not taken up, it can scorch, and on a slope it leaves the garden entirely. Over-application is the only way to damage a lawn with a feed.
Last reviewed 26 September 2026