Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of determining when you can plant achimenes is to refer to the USDA zone info for Petaluma.

Planting Calendar for Achimenes

Frost tolerance for achimenes:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You really shouldn't plant achimenes until after all chance of frost has passed because they require warm weather.

The earliest that you can plant achimenes in Petaluma 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 fully mature. Starting your achimenes indoors is a great way to get them started a few weeks earlier.

Last Frost Date

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

Always keep in mind that USDA zone info for Petaluma may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Petaluma you get a frost after February 15 be ready to protect your achimenes if you have one of those late frosts.

USDA Zone Info for Petaluma

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 Petaluma

You may be interested in your other planting guides for Petaluma.