One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By looking at the USDA zone info for Sonoma you will be able to figure out when it's a good idea to plant xerianthemum.

Planting Calendar for Xerianthemum

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

Since xerianthemum do ok in moderate cold you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant xerianthemum in Sonoma 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 xerianthemum and expect a good harvest is probably September. You probably don't want to wait any later than that or else your xerianthemum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your xerianthemum indoors.

Last Frost Date

In Sonoma the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 25°F.

Since the USDA zone info for Sonoma is just an average the actual date of last frost is different every year. Since half of the time in Sonoma there is a last frost after February 15 be ready to cover your xerianthemum if you have a surprise 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.