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.

A way of estimating when it's a good idea to plant saxifraga is to consult the USDA zone info for Sonoma.

Planting Calendar for Saxifraga

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

Since saxifraga are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than more sensitive plants.

The earliest that you can plant saxifraga 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 saxifraga and expect a good harvest is probably September. If you wait any later than that and your saxifraga may not have a chance to fully mature. If you are starting your saxifraga indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is February 15 in Sonoma. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Sonoma may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Sonoma it frosts late in the year after February 15 so just be sure to be ready to cover your saxifraga 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.