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

A common way of making a decision about when it's a good idea to plant astilbe is to refer to the USDA zone info for Windsor.

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.

Since astilbe are one of those plants that can tolerate a tiny bit of cold weather you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant astilbe in Windsor 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 grow to maturity. If you are starting your astilbe indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Windsor the average date of last frost happens on February 15. You should expect an average low temperature of 25°F in the coldest months of winter.

Since the USDA zone info for Windsor may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Windsor it frosts late in the year after February 15 be ready to protect your astilbe if you have one of those late frosts.

USDA Zone Info for Windsor

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 Windsor

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