There's no single right answer to "how often should I mow," because the honest answer changes every few weeks as the season shifts. Grass that needs a cut every five days in late May can go two full weeks without much change in August. Here's how mowing frequency actually breaks down across an Ontario growing season, and how to read your own lawn instead of guessing.
The One-Third Rule
Before frequency, there's a rule that matters more: never cut more than one-third of the grass blade height in a single mow. Scalping a lawn that's grown too long stresses the roots and opens the door to disease and weeds. This rule is also why mowing frequency has to flex with growth rate rather than sitting on a fixed weekly calendar.
Spring (Late April–Early June)
This is the fastest growth window of the year in the GTA West. Cool nights, regular rain, and longer days push grass hard. Most lawns need a cut every 5–7 days during peak spring growth. Skipping a week here is usually where lawns start looking shaggy and uneven compared to neighbours who stayed on schedule.
Summer (Late June–August)
Growth slows once the heat sets in, especially during dry stretches. Weekly mowing is still common, but many homeowners shift to bi-weekly without any visible difference — particularly if they're not irrigating heavily. Mowing too short in summer heat is a bigger risk than mowing too infrequently; longer grass shades its own roots and holds moisture better during hot weeks.
Fall (September–Late October)
Growth picks back up as temperatures drop and rain returns, similar to spring. Weekly mowing often comes back into play through September, then tapers as growth slows toward late October. The final cut or two of the season should be slightly shorter than usual, which helps prevent matting and snow mould over winter.
So: Weekly or Bi-Weekly?
If you want a single answer: weekly mowing keeps a lawn looking consistently sharp through the fastest-growing months, while bi-weekly is a reasonable compromise during slower growth periods or for homeowners prioritizing cost over a manicured look. Most of our customers land on weekly in spring and fall, and either weekly or bi-weekly through summer depending on their lawn and budget. For a closer look at that specific decision, see our guide on weekly vs. bi-weekly mowing.
The Easiest Approach
Rather than tracking growth rates yourself, most homeowners just want it handled. When we quote a property, we look at the grass type, sun exposure, and your goals, and recommend a schedule — then adjust it through the season as growth speeds up or slows down. That's the value of having someone watching the lawn regularly instead of mowing on a fixed date regardless of conditions.