One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's the best time to plant zucchini by referring to the USDA zone info for Phoenix.

Planting Calendar for Zucchini

Frost tolerance for zucchini:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant zucchini until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant zucchini in Phoenix is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant zucchini and expect a good harvest is probably August. Any later than that and your zucchini may not have a chance to fully mature. You can get started a little bit earlier by starting your zucchini indoors.

Last Frost Date

In Phoenix the average date of last frost happens on March 15. It might get as low as 10°F during the coldest months of winter.

Keep in mind that USDA zone info for Phoenix may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Phoenix there is a last frost after March 15 so just be sure to be ready to cover your zucchini if you have a surprise late frost.

USDA Zone Info for Phoenix

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°F

This means that on a really cold year, the coldest it will get is 10°F. On most years you should be prepared to experience lows near 15°F.

Plants to Grow in Phoenix

You may be interested in your other planting guides for Phoenix.