What to Plant in Phoenix in March
By March in Phoenix, your spring garden is in the ground and growing. The main focus shifts from planting to care — fertilizing, increasing watering, and watching for the first flowers and fruit. There are still a few things to plant, but March is primarily the month your spring garden starts delivering.
Still Possible to Plant in March
Cucumbers and Summer Squash (Early March)
If you missed the late February window, direct sow cucumbers and summer squash in early March (by March 15). You'll get a harvest, though shorter than February-planted crops. After mid-March the heat arrives fast and the window narrows further.
Green Beans (Through Mid-March)
Direct sow green bean seeds through mid-March. Beans planted in early March will produce in early May and are reliable right up to the heat. After March 15 it's getting late — plants may produce some harvest but will struggle as temperatures approach 95°F.
Basil (March Through April)
Basil loves Phoenix spring and summer heat. Transplants or seeds go in anytime March through April. One of the few crops with a long productive window here — basil thrives until monsoon humidity promotes fungal disease in August.
Okra (Late March)
Start okra seeds in late March — it needs warm soil (70°F+) to germinate well and actually performs better when it has to struggle a bit in spring heat. Okra produces all summer in Phoenix when most other crops are resting. One of the true desert-adapted vegetables.
March Garden Tasks
Fertilize
Tomatoes and peppers in the ground since January need their first fertilizer boost. Use a balanced fertilizer (8-8-8 or similar) in early March. Once you see flower buds forming, switch to a lower-nitrogen, higher-phosphorus formula to promote fruit set rather than leaf growth.
Increase Watering
March temperatures are rising — adjust your drip timer from twice-weekly to three times weekly. Tomatoes especially need consistent moisture from first flower through harvest to prevent blossom end rot and fruit cracking.
Harvest Remaining Cool-Season Crops
Lettuce, spinach, and arugula will bolt (send up a seed stalk and go bitter) as temperatures hit 75–80°F consistently. Don't wait — harvest aggressively in March before the flavor turns. Kale and Swiss chard are more heat-tolerant and can be harvested into April.
Install Cages and Trellises
If you haven't already, install tomato cages and cucumber trellises in March before plants get too large. Doing this while plants are small avoids root disturbance later.
What NOT to Plant in March in Phoenix
- Tomatoes — Past the deadline. Won't have enough production time before summer heat.
- Peppers and eggplant — Can try in early March but very late. Buy from nursery if available.
- Cool-season crops — Lettuce, kale, broccoli, peas are all done for spring. Next window is October.
Frequently Asked Questions
What can I plant in Phoenix in March?
Cucumbers and summer squash (early March), green beans (through mid-March), basil, and okra (late March). March is primarily a maintenance and harvesting month — your spring garden is already established.
Can I still plant tomatoes in March in Phoenix?
No — tomatoes planted in March won't have enough time before Phoenix heat exceeds 95°F in late May and shuts down fruit set. The tomato window in Phoenix closes February 15. Skip tomatoes and focus on faster-maturing cucumbers, beans, and squash.
When do Phoenix spring crops start producing?
Tomatoes planted in January typically begin producing in April. Cucumbers and squash planted in late February produce in April–May. Beans planted in February produce in April. March is when you see first flowers and early harvests begin.
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