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.

In Sonora you can figure out when you can plant hardy hibiscus by looking at the USDA zone info.

Planting Calendar for Hardy Hibiscus

Frost tolerance for hardy hibiscus:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Hardy Hibiscus are very cold tolerant which tells us that you can get them planted much earlier than more sensitive plants.

The earliest that you can plant hardy hibiscus in Sonora is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant hardy hibiscus and expect a good harvest is probably October. Any later than that and your hardy hibiscus may not have a chance to grow to maturity. If you are starting your hardy hibiscus indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Sonora the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 20°F.

Always keep in mind that USDA zone info for Sonora is not always accurate and the actual date of last frost changes from year to year. Half of the time in Sonora you get a frost after February 15 so always be ready to cover your hardy hibiscus in the event of one of those late frosts.

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.