Mowing height in summer
In heat, raise the cut to 5–6 cm. Taller grass shades its own roots, holds moisture and crowds out weeds.
- When
- Jun 1 – Aug 31 (northern hemisphere) · Dec 1 – Feb 28 (southern)
- Repeat
- Every 7–10 days
- For
- Cool-season lawns (ryegrass, fescue, bluegrass)
- Needs
- mower
- Rule
- su-mow-high · Hessayon; Mellor; Walheim
In heat, raise the height to 5–6 cm — taller grass shades the roots and holds moisture.
Why taller in summer
A short lawn looks tidy on the day it is cut, but it suffers for the rest of the week. Less leaf means less shade on the soil, faster drying and a smaller root system, because root depth follows leaf height. A taller canopy keeps the soil cooler and denies light to crabgrass seed, which needs it to germinate.
The settings
- Cool-season grass (ryegrass, fescue, bluegrass): 5–6 cm, about 2–2½ in, from June to the end of August.
- Mower markings are often optimistic. Check the actual cut height with a ruler on a flat surface.
- Warm-season grasses have their own heights: Bermuda 1.5–4 cm, Zoysia 2.5–5 cm, St. Augustine 6–10 cm.
How often
Every 7–10 days, and less often in a drought when the grass slows down. Never take off more than a third of the blade in one cut. If the lawn has grown to 9 cm, cut it to 6, not to 4; if you are well behind, bring it down over two cuts a few days apart.
Blade and clippings
Keep the blade sharp: a torn tip loses water and browns within a day in heat. Leave fine clippings on the lawn, or use a mulching mower; they return nitrogen and hold moisture. Collect them only if they lie in clumps. Do not mow a lawn that is waterlogged or under drought stress; wait for it to recover.
Pair the higher cut with deep, infrequent watering in the morning.
Sources
- D.G. Hessayon — The Lawn Experthessayon
- David Mellor — The Lawn Biblemellor
- Lance Walheim — Lawn Care For Dummieswalheim