The USDA Zone info is a great tool for gardeners to help us determine 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.

The first opportunity to plant regal geranium in Sonora should be estimated by checking out the USDA zone info.

Planting Calendar for Regal Geranium

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

Since regal geranium do ok in moderate cold you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant regal geranium 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 regal geranium and expect a good harvest is probably September. You probably don't want to wait any later than that or else your regal geranium may not have a chance to fully mature. Starting your regal geranium indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Sonora. You can expect an average low temperature of 20°F in the coldest months of winter.

Since the USDA zone info for Sonora is an average the actual date of last frost will vary from year to year. Since half of the time in Sonora last frost occurs after February 15 be ready to protect your regal geranium if you have 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.