| City | Aerate + overseed | Pre-emergent | Season |
|---|
| Phoenix | Nov 4 – Nov 19 | Dec 15 – Jan 5 | 363 days |
| Tucson | Oct 18 – Nov 2 | Dec 30 – Jan 20 | 331 days |
| Flagstaff | Jul 30 – Aug 14 | May 14 – Jun 4 | 116 days |
All Arizona station records (171)
Every NOAA weather station in Arizona with complete 1991–2020 frost normals — pick
the one nearest you (similar elevation matters more than plain distance).
Not sure which station to trust? Use the
ZIP code lookup
for the quick answer, or pick the station whose terrain most resembles your yard.
Lawn timing geography of Arizona
Across the 174 Arizona locations with complete 1991–2020 frost
normals, the average last spring frost — the anchor for pre-emergent and spring
work — ranges from Jan 4 (Bullhead City) to Jun 23
(Flagstaff 4 SW), a spread of about 24 weeks driven by elevation, latitude, and terrain.
The same job can be weeks apart at opposite ends of the state, which is why a
state-level date is only a starting point — pick the location nearest your yard and
plan from its calendar.
The Arizona lawn year in one paragraph
Arizona lawns run on two opposite calendars. Tall fescue and bluegrass lawns treat early fall as the main event — aerate, overseed, feed — with spring for pre-emergent and light feeding. Bermuda and Zoysia lawns flip it: establish and feed from late spring through summer, stop nitrogen 6–8 weeks before frost, and accept winter brown as normal. Identify your grass first; every date on this page depends on it. Details by task: when to overseed in Arizona, when to aerate in Arizona, when to apply crabgrass pre-emergent in Arizona, and more above.