The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of figuring out when it's a good idea to plant gomphrena is to look at the USDA zone info for Sonora.

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.

Gomphrena do ok in a tiny bit of cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant gomphrena in Sonora 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. Any later than that and your gomphrena may not have a chance to grow to maturity. If you are starting your gomphrena indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Sonora. It might get as low as 20°F during the coldest months of winter.

Since the USDA zone info for Sonora may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Sonora you get surprised by a frost after February 15 so just be sure to be ready to cover your gomphrena in the event of a late frost.

USDA Zone Info for Sonora

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Sonora

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