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.

One way of getting a good idea when to plant gomphrena is to use the USDA zone info for Phoenix.

Planting Calendar for Gomphrena

Frost tolerance for gomphrena:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant gomphrena a bit earlier in the year because they are barely cold tolerant.

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

The last month that you can plant gomphrena and expect a good harvest is probably September. If you wait any later than that and your gomphrena may not have a chance to fully mature. Starting your gomphrena indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Phoenix the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Phoenix is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Phoenix you get a frost after February 15 be ready to cover your gomphrena if you have one of those late frosts.

USDA Zone Info for Phoenix

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Phoenix

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