New sod roots best when soil is warm but air temperatures are moderate. In Montreal that means mid-May to late June, then again from late August through early October.
July installs are possible but demand daily watering; a lawn laid in a heat wave without irrigation will shrink at the seams within a week.
Preparation matters more than the sod itself. We strip the old turf, correct the grade away from the foundation, and add 5–8 cm of screened topsoil before a single roll goes down.
For the first 30 days, water deeply every morning, keep foot traffic off, and wait until the roots resist a gentle tug before the first mow.
“Late spring and early fall give new sod the cool nights and steady moisture it needs to root before stress hits.”