Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Simi Valley should be reviewed to figure out 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 do ok in moderate cold which means that you can get them planted just a bit earlier than more sensitive plants.

The earliest that you can plant astilbe in Simi Valley 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. You probably don't want to wait any later than that or else 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 couple of weeks earlier.

Last Frost Date

On average the last frost is on February 15 in Simi Valley. You can expect an average low temperature of 25°F in the coldest months of winter.

Just be sure to remember that USDA zone info for Simi Valley is just an average and the actual date of last frost will vary from year to year. Half of the time in Simi Valley it frosts late in the year after February 15 so just be sure to be ready to cover your astilbe if you have a surprise late frost.

USDA Zone Info for Simi Valley

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 Simi Valley

You may be interested in your other planting guides for Simi Valley.