One of the first steps you take when you are estimating your gardening schedule is find your 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.

You will be able to determine when it's a good idea to plant doronicum by referring to the USDA zone info for Sonoma.

Planting Calendar for Doronicum

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

Doronicum tend to make it in a little bit of cold which tells us that you can plant them a little bit earlier in the year than more sensitive plants.

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

Last Frost Date

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

Just be sure to remember that USDA zone info for Sonoma is an average and the actual date of last frost is different every year. Half of the time in Sonoma there is a last frost after February 15 so make sure that you are prepared to cover your doronicum in the event of 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.