One of the first steps you take when you are estimating 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.

By referring to the USDA zone info for Sonoma you should be able to estimate when you can plant argyranthemum.

Planting Calendar for Argyranthemum

Frost tolerance for argyranthemum:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You can not plant argyranthemum until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant argyranthemum in Sonoma is March. However, you really should wait until April if you don't want to take any chances.

The last month that you can plant argyranthemum and expect a good harvest is probably September. If you wait any later than that and your argyranthemum may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your argyranthemum indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Sonoma. In the coldest months of winter you can expect an average low temperature of 25°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Sonoma and it is different every year. Half of the time in Sonoma it frosts late in the year after February 15 so make sure that you are ready to cover your argyranthemum 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.