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.

One way of making a decision about when it's possible to plant argyranthemum is to consult the USDA zone info for Santa Rosa.

Planting Calendar for Argyranthemum

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

It's a bad idea to plant argyranthemum until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant argyranthemum in Santa Rosa 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. Any later than that and your argyranthemum may not have a chance to really do well. Starting your argyranthemum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Santa Rosa. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Santa Rosa may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Santa Rosa you get surprised by a frost after February 15 be ready to protect your argyranthemum in the event of a late frost.

USDA Zone Info for Santa Rosa

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 Santa Rosa

You may be interested in your other planting guides for Santa Rosa.