One of the first steps you take when you are making a decision about your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Sonoma should be reffered to in order to figure out when it's a good idea to plant violas.

Planting Calendar for Violas

Frost tolerance for violas:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant violas a lot earlier in the year because they are very cold tolerant.

The earliest that you can plant violas 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 violas and expect a good harvest is probably October. Any later than that and your violas may not have a chance to grow to maturity. Starting your violas indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Sonoma the average date of last frost happens on February 15. It might get as low as 25°F during the coldest months of winter.

Remember that USDA zone info for Sonoma may not be accurate from year to year and the actual date of last frost will vary from year to year. Half of the time in Sonoma it frosts late in the year after February 15 so always be ready to cover your violas in the event of 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.