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.

The USDA zone info for Sonora can be used to determine when it's a good idea to plant diascia.

Planting Calendar for Diascia

Frost tolerance for diascia:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Diascia are moderately cold tolerant which means that you can plant them earlier than other plants that might not handle the cold.

The earliest that you can plant diascia 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 diascia and expect a good harvest is probably October. Any later than that and your diascia may not have a chance to really do well. If you are starting your diascia indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Sonora. It might get as low as 20°F during the coldest months of winter.

Keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Sonora and it can change quite a bit from year to year. Half of the time in Sonora there is a last frost after February 15 so make sure that you are ready to protect your diascia if you have 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.