Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By reviewing the USDA zone info for Sonoma it's possible to estimate when 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.

You can plant diascia a little bit earlier in the year because they do well in moderate cold.

The earliest that you can plant diascia in Sonoma 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. If you wait any later than that and your diascia may not have a chance to really do well. Starting your diascia 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 Sonoma. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Sonoma is an average the actual date of last frost will vary from year to year. Since half of the time in Sonoma there is a last frost after February 15 be ready to protect your diascia if you have a late frost.

USDA Zone Info for Sonoma

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 Sonoma

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