Cool-season lawns: why then
Keep mowing as long as the grass keeps growing — usually until a couple of weeks after the first frost. Take the final cut slightly shorter than summer height (never scalped): shorter winter turf mats less under snow and resists snow mold. Leaves must be mulched or removed before snow regardless.
Warm-season lawns: why then
Warm-season growth slows sharply as nights cool and stops when frost sends the lawn into dormancy — typically within two weeks of the first frost, after which the lawn browns and mowing is done for the year. In frost-free areas growth merely slows, and occasional winter mowing continues.
Not sure which family your New Mexico lawn belongs to? If it stays green all winter and suffers in July, it's cool-season; if it goes uniformly brown after frost and loves August, it's warm-season. The grass guides settle it in two minutes.
Frequently asked questions
When should I stop mowing for the year in New Mexico?
It depends on your grass. For cool-season lawns (tall fescue, bluegrass) the New Mexico window is Sep 29 – Nov 27; for warm-season lawns (Bermuda, Zoysia) it's Sep 22 – Nov 20. The two families run on opposite calendars, so identify your grass first.
Why do the dates vary within New Mexico?
Because climate does. The dates here are calculated separately for each city from its own NOAA 1991–2020 frost records, and elevation, latitude, and terrain spread them across New Mexico — the same task can be a week or two apart between towns. That local spread is exactly what generic national advice misses.
What if I miss the window?
Better to skip than to force it. Doing this job in the wrong season stresses the lawn more than not doing it at all — set a reminder for the next window.