One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant dahlias in Phoenix can be determined by referring to the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

Since dahlias require warm weather it's important to wait until after the last frost when the weather gets warmer before you can plant them.

The earliest that you can plant dahlias 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 dahlias and expect a good harvest is probably August. You probably don't want to wait any later than that or else your dahlias may not have a chance to fully mature. You can get started a few weeks earlier by starting your dahlias indoors.

Last Frost Date

The average date of last frost is March 15 in Phoenix. You can expect an average low temperature of 10°F in the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Phoenix and it can change quite a bit from year to year. Half of the time in Phoenix it frosts late in the year after March 15 so always be ready to cover your dahlias if you have one of those late frosts.

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.