Advanced options
Always check the rate on YOUR product's box: over-application scorches grass in stripes that last all summer (the classic spreader-overlap signature). A wheeled spreader set to half rate in two passes at right angles gives the evenest coverage. Apply to damp grass with rain due, or water in within 2-3 days.
What The Lawn Feed Calculator Works Out
- Product needed: lawn area x application rate, converted from grams to kilograms. Spring and summer feeds run about 35 g/m2, combined feed-weed-and-mosskiller 70 g/m2 and autumn feeds 70 to 100 g/m2, so a 100m2 lawn wants 3.5kg of spring feed and 7kg of weed and feed.
- Application tips: spring feeds are high-nitrogen for leaf growth; autumn formulations flip to potassium and phosphorus for roots and winter hardiness. Applying the spring bag in October produces soft growth for the first frost to execute.
- Rate from your box (advanced): the box's own number outranks any default, because nitrogen at the right rate greens and thickens while double-dosing scorches brown. Type it here and every figure updates.
- Overlap allowance (advanced): adds a percentage for the spreader overlap and spillage on the path that always claims some product. 5% to 10% is realistic on an awkward lawn; keep it at zero if you are weighing out by marked square.
- Pack size and packs to buy (advanced): lawn feed is sold in 1kg to 3.5kg boxes and 10kg or 20kg bags. The card shows how many packs, what is left over and how many square metres each pack covers at your rate.
- Cost per application and annual total (advanced): packs x price, with a cost per square metre and per kilogram, multiplied by the number of applications a year. A 10kg bag of straight lawn feed is typically GBP 15 to GBP 30; weed-and-feed products about double.
- Spreader setting (advanced): for a wheeled spreader the rate is halved and applied in two passes at right angles, which averages out the spreader's own errors; the sub-line gives a calibration check for a 10m2 strip. For hand broadcasting it gives the grams per 2m x 2m marked square and how many squares your lawn has.
- Seasonal programme table (advanced): kilograms and packs for each treatment in a typical UK year, plus the autumn top-dressing at about 2kg/m2. Mowing little and often at a third off the blade does more for density than any bag, and yellow from compaction, shade or drought is not fixed by fertiliser.