How Often Should You Mow Your Lawn in Guelph?

The one-third rule decides everything

Never remove more than a third of the grass blade in a single cut. Cut off more and the plant panics — it stops growing roots and burns its reserves regrowing leaf instead. That’s why a lawn that gets scalped every two weeks often looks worse than a lawn cut weekly at the right height.

We mow at roughly 3 inches. For grass kept at 3 inches, the one-third rule means cutting again when it reaches about 4 to 4.5 inches. In a Guelph spring, that takes about a week. In a dry July, it can take two or three.

Month by month in Guelph

• Late April – May: weekly, no exceptions. Spring flush is the fastest growth of the year.
• June: weekly. Growth is still strong, and weekly cuts keep clippings short enough to feed the lawn instead of smothering it.
• July – August: weekly if you irrigate, biweekly is usually fine if you don’t. Cool-season grasses slow down or go semi-dormant in heat.
• September: back to weekly. Cooler nights and fall rain wake the lawn right back up.
• October: weekly to biweekly, tapering off. Final cut usually lands late October or early November.

Why we don’t recommend "every 10 days"

Splitting the difference sounds efficient, but it drifts your cut day later every week, which makes routes — and your lawn — unpredictable. A fixed weekly or biweekly day keeps the one-third rule intact and means you always know when the crew is coming.

What this looks like as a service

Most of our Guelph clients run weekly from May through October with mowing from $40 per cut, including trimming, edging and a full blowdown. Biweekly works for slower, shadier lawns — we’ll tell you honestly which one your property needs when we quote it.

What “weekly” really means in a wet Guelph May

A weekly schedule is a target, not a promise that the lawn gets cut on Tuesday at 2 p.m. no matter what. In a wet spring, three days of rain can push a Tuesday route to Thursday — and the lawn that was 4 inches on Tuesday is 5.5 by Thursday. That is when a good crew double-cuts: a first pass at a higher setting, then a second at the normal height, so the one-third rule still roughly holds and the lawn is not left with windrows of wet clippings smothering it.

The other thing a wet week changes is traffic. Mowers on saturated turf leave ruts and compact the soil for the rest of the season, so on the worst days we would rather come back the next morning than carve tracks into your lawn to hit a calendar date.

Bag the clippings or leave them?

Leave them, almost always. Clippings are mostly water and nitrogen; mulched back into the lawn they return a meaningful share of the fertilizer the lawn needs each year and they do not cause thatch (thatch is stems and roots, not blades). The exceptions are the ones you would guess: grass that got away and is being cut long and wet, a lawn with active disease like red thread, or the final fall cut when you are also pulling leaves off.

Making biweekly work if that is your budget

Biweekly service is a real option on slower lawns, but it has to be managed or it turns into scalping every second Wednesday. Keep the cutting height at the top of the range — 3 to 3.5 inches — so the lawn has room to grow without breaking the one-third rule. Accept weekly visits in May and early June when growth is fastest, then drop to biweekly from late June. And do not fertilize heavily on a biweekly schedule; you are paying to make the grass grow faster than you are cutting it.

What does not work is biweekly on an irrigated, fertilized lawn in spring. Those lawns put on two inches a week and the only way to cut them every fourteen days is to scalp them, which is how you end up with a brown, stressed lawn by July.

Signs you have the frequency wrong

• Yellow or brown tips the day after a cut: too much blade removed at once — shorten the interval or raise the deck.
• Clumps of clippings left on the surface: the grass was too long for one pass.
• A lawn that looks great for two days and shaggy for five: the interval is too long for the growth rate.
• Dust and tracks with barely any clippings: you are cutting more often than the lawn is growing — common in a dry August. Skip it.