Well, hey there, friends! Tim Burr here, and I've got exciting news: the finish line of summer is in sight. By late August and into September, the worst of the heat starts to loosen its grip, and we roll into the single best planting season of the entire Phoenix year — fall. Smart desert gardeners plant in fall, not spring, and right now is the time to prep. Let me get you ready.
Why fall is the #1 planting season in Phoenix
This is the most important thing I can teach a Phoenix gardener, so let me say it plainly: fall, not spring, is the best time to plant in the low desert. Here's why. When you plant in fall, the air is cooling but the soil stays warm well into the season — and warm soil drives fast root growth. Your new plants get the entire mild fall, the gentle winter, and the lovely spring to establish a deep, strong root system before they ever face a brutal summer. By the time next June arrives, they're tough, established veterans.
Plant the same thing in spring, and it has just a few weeks to establish before getting slammed by 110°F heat — a much harder road. Fall planting gives your plants a six-month head start. It's the single biggest reason some yards thrive and others struggle.
September prep: get the yard ready
September is your runway. Use it to set up a successful fall planting season:
- Make your plant plan now. Decide what's going where — shade trees, privacy screens, color, accents — and size everything to mature dimensions so you don't overcrowd.
- Clear and assess beds. Pull summer weeds (which exploded during the monsoon), remove any plants that didn't survive summer, and note bare spots that need filling.
- Check and tune your irrigation. Before the planting rush, walk your drip system: clear clogged emitters, fix leaks, and confirm every zone is delivering deep water. Plan to adjust the timer to less frequent watering as temps drop.
- Refresh mulch. Top up mulch and decomposed granite that thinned out over summer to keep soil cool and weeds down.
- Do your soil prep and percolation tests for any new tree spots (remember the caliche drainage check!) so holes are ready when planting weather hits.
What to plant in fall
Once nights start cooling (typically late September into October), it's go time for nearly everything:
- Trees: The very best time to plant shade and flowering trees — palo verde, mesquite, desert willow, fruitless olive, and more. Fall-planted trees establish dramatically better than spring ones.
- Shrubs and privacy screens: Green Hopseed, Texas sage, Yellow Bells, and other screens and color shrubs root in beautifully now.
- Cacti, agave, and succulents: Plant while soil is still warm; ease off water as the season cools.
- Cool-season color and veggies: As nights cool, it's time for petunias, snapdragons, and the cool-season vegetable garden — fall and winter are prime growing for these here.
- Wildflower seeds: Sow desert wildflower seed in fall for a spectacular spring bloom.
Adjust your care for the cooling season
As the weather shifts, so should your routine:
- Dial back watering. As temperatures drop, plants need water less often. Stretch the days between deep soaks and update your irrigation timer — overwatering in cool weather invites rot.
- Resume pruning and feeding. Fall is a good window for shaping and a light feeding to support root growth (you avoided heavy pruning all summer — now you can tidy up).
- Plan for frost. Note which tender plants might need cover on the coldest winter nights, and keep frost cloth handy for later.
Get a jump on it
The gardeners with the best yards are the ones who plant in fall while everyone else waits for spring. Prep in September, plant as it cools, and you'll spend next summer watching established, thriving plants instead of nursing struggling new ones. It's the smartest move in desert gardening — and the season is almost here.
Start building your fall planting list now. Browse Fast Growing Favorites, Shade Trees, and Low Water (Drought-Proof) plants to plan your best planting season yet. We deliver to your door, back every plant with our survival guarantee, and can install your whole fall landscape for you.
🌵 Tim's Tip: Use September to walk your drip irrigation system before the fall planting rush — clear clogged emitters, fix leaks, and confirm every zone delivers a deep soak. Then, as nights cool, dial the timer back to less frequent watering. Overwatering in cool weather is a top way to lose plants, so adjusting the schedule for the season is just as important as the planting itself.
Frequently Asked Questions
Is fall really the best time to plant in Phoenix?
Yes — fall, not spring, is the #1 planting season in the low desert. When you plant in fall, the air is cooling but the soil stays warm, driving fast root growth, and your plants get the whole mild fall, winter, and spring to establish before facing a brutal summer. Spring plantings get only weeks before the heat hits — a much harder road.
When exactly should I start planting in fall?
Generally once nights begin cooling, typically late September into October. Use early-to-mid September to prep: make your plant plan, clear and weed beds, tune your irrigation, refresh mulch, and do soil and drainage prep (including the caliche percolation test) for any new tree spots so you're ready to plant the moment the weather turns.
What should I plant in fall?
Almost everything: shade and flowering trees (the very best time), privacy screens and color shrubs like Hopseed, Texas sage, and Yellow Bells, plus cacti and agave while the soil's still warm. As nights cool, add cool-season color and the winter vegetable garden, and sow desert wildflower seed for a spectacular spring bloom.
How should I change my watering in fall?
Dial it back. As temperatures drop, plants need water less often — stretch the days between deep soaks and update your irrigation timer. Cool-weather overwatering invites rot, so easing off as the season cools is important. Newly planted material still needs regular water to establish, just less than in summer.
Can I still prune and fertilize in fall?
Yes. After avoiding heavy pruning all summer (to protect bark from sunburn), fall is a good window to shape plants and give a light feeding to support root growth. It's also the time to note which tender plants might need frost cover later and to keep frost cloth handy for the coldest winter nights.
Summer's almost behind us, friends — and the best planting of the year is right ahead. Let's get ready to grow. — Tim 🌵
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