Before planting it is a good idea to find your USDA Zone info to figure out 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.

By looking at the USDA zone info for Sebastopol you will be able to estimate when you can plant astilbe.

Planting Calendar for Astilbe

Frost tolerance for astilbe:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Astilbe are one of those plants that can tolerate a tiny bit of cold weather which means that you can get them planted just a bit earlier than other frost tender plants.

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

The last month that you can plant astilbe and expect a good harvest is probably September. Any later than that and your astilbe may not have a chance to really do well. If you are starting your astilbe indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on February 15 in Sebastopol. In the coldest months of winter you can expect an average low temperature of 20°F.

Since the USDA zone info for Sebastopol is just an average the actual date of last frost changes from year to year. Half of the time in Sebastopol you get a frost after February 15 so just be sure to be ready to protect your astilbe if you have one of those late frosts.

USDA Zone Info for Sebastopol

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Sebastopol

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