Fall is planting season in Phoenix, even when October still feels like summer. In a KJZZ interview during one of the hottest Phoenix Octobers on record, a master gardener who manages the garden at Arizona State University's Polytechnic campus explained why.
Why fall works
It's about daylight more than temperature. "The days are definitely getting shorter once we pass the fall equinox at the end of September," and shorter days mean "things grow much slower." So the window is October and early November, "before it gets super dark in December and January," because "plants need sunlight to photosynthesize and to grow, and so things kind of really slow down come December."
Warm days still help: "we need the warmth of the day, maybe not 100 and 10 warmth, but to allow roots to grow."
Why plant now, not in spring
Landscape plants that go in during the fall have the winter to settle in. As she put it about replacing cacti lost to the summer heat, now is "a great time to plant more landscape plants, so they get established over the winter. So they're bigger and can survive our heat."
Fit the city's approval into the calendar
If you're replacing a lawn with a city rebate, approval comes before planting. Phoenix's review can take up to 3 weeks, and you can't remove any grass until you have the go-ahead. That makes the calendar simple:
- October: measure your lawn, apply, and wait for approval.
- Late October to early November: once approved, remove the grass and plant while the days are still long enough.
- Winter: new plants settle in before next summer.
Start with your number: see your rebate, then read the Phoenix step-by-step guide.