The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By checking out the USDA zone info for Santa Rosa it's a good idea to determine when it's possible to plant achimenes.

Planting Calendar for Achimenes

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

You should not plant achimenes until after the last frost when the weather gets warmer because they require warm weather.

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

Last Frost Date

The average date of last frost is February 15 in Santa Rosa. In the coldest months of winter you should expect an average low temperature of 25°F.

Remember that USDA zone info for Santa Rosa is just an average and the actual date of last frost is different every year. Since half of the time in Santa Rosa there is a last frost after February 15 be ready to cover your achimenes in the event of one of those late frosts.

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.