One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

A common way of making a decision about when to plant pentas is to check out the USDA zone info for Sonoma.

Planting Calendar for Pentas

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

Since pentas do not do well in cold weather you have to wait until after the last frost before you can plant them.

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

Last Frost Date

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

Since the USDA zone info for Sonoma is not always accurate the actual date of last frost can change quite a bit from year to year. Since half of the time in Sonoma you get a frost after February 15 be ready to cover your pentas if you have one of those late frosts.

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.