How short should you cut a Perth lawn?

Cut too low and you take off the leaf, which is the part doing the photosynthesis. What's left is stem and runner, and stems don't feed the plant. The lawn goes yellow or brown, not because it's dying but because you've removed the green.

Then the second problem arrives. With no leaf canopy, sunlight hits the soil directly. Soil temperature climbs, moisture evaporates faster, and on a Perth summer day that's a serious amount of water gone. The lawn gets thirsty between waterings and the roots, which mirror the leaf above them, shrink back and go shallow.

And the third. Bare soil in full sun is exactly where weed seeds want to be. Every scalped patch is an open invitation, which is why the thinnest lawns are always the weediest. We've written about that link in why the best weed control is a thick lawn.

Longer leaf means deeper roots, cooler soil, less evaporation and fewer weeds. That's the whole argument.

Never take off more than a third of the leaf blade in a single cut.

If the lawn is at 60mm, cut to 40mm, not 25mm. If it's got away from you over a long weekend, bring it down over two or three mows a few days apart rather than one dramatic haircut.

This is the rule that saves lawns after holidays. Coming home to a jungle and dropping the mower to its lowest setting is the single most damaging thing most people do to their turf all year.

Different grasses want different heights, and the difference is bigger than most people expect. If you're not sure what you've got, our guide to couch, buffalo and kikuyu will sort it out.

Couch is the low one. It's fine-leafed, it spreads hard, and it tolerates a close cut better than anything else in a Perth backyard, which is why it's on the sports fields. Roughly 15mm to 25mm suits it, and it will still look sharp at the lower end if you're mowing often enough to keep to the one third rule.

Buffalo is the high one. It's broad-leafed and it carries its growing points up on the stem, so cutting it low removes them and the lawn struggles to recover. Around 30mm to 50mm, and closer to the top of that range in shade or through summer. Most struggling buffalo lawns in Perth are simply being cut too short.

Kikuyu sits in between. It's vigorous, it grows fast, and it'll handle roughly 25mm to 40mm. The main challenge with kikuyu isn't height, it's keeping up with it in spring.

Whatever you've got, raise the height going into summer. A slightly longer lawn shades its own soil, and in January that matters more than the extra millimetres show.

A sharp blade slices the leaf cleanly. A blunt one tears it, and torn grass browns off at the tip within a day or two. If your lawn always looks slightly off colour the day after mowing, that's the blades, not the fertiliser.

Sharpen or replace them at the start of the season and again partway through if you're mowing sandy ground, because sand blunts steel fast.

From September the growth rate climbs, and the honest answer is that spring lawns need cutting more often than people do it. Mowing weekly at the right height beats mowing fortnightly and taking twice as much off, every time.

If you're catching clippings every cut on sandy Perth soil, consider dropping the catcher occasionally when the clippings are short. Fine clippings break down quickly and return nutrition to a profile that badly needs organic matter, which pairs well with top dressing doing the same job from above.

Mowing height is a lever, not a cure. If the lawn is thin, patchy or hard underfoot, no setting on the mower will fix it, because the problem is under the surface. That's usually compaction, thatch or exhausted sand, and the fixes are core aeration, scarifying or top dressing depending on which one you've got. We've laid out how to tell the difference in scarifying, coring or top dressing.

Cut couch low, buffalo high, kikuyu in between. Never take more than a third off at once. Keep the blades sharp, mow more often through spring, and lift the height going into summer.

Mowing is one part of a lawn program, not the whole thing. Our complete lawn care packages roll mowing, feeding and seasonal care into one scheduled plan so the height, the timing and the feeding all line up. Tell us about your lawn through the quote form and we'll reply within one business day with something tailored to your turf, not a template.