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.

The best time to plant astilbe in Fairfax can be determined by reviewing the USDA zone info.

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 well in some cold which tells us that you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant astilbe in Fairfax 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. If you wait any later than that and your astilbe may not have a chance to fully mature. You can get started a little bit earlier by starting your astilbe indoors.

Last Frost Date

The average date of last frost is February 15 in Fairfax. In the coldest months of winter you can expect an average low temperature of 25°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Fairfax and it changes from year to year. Since half of the time in Fairfax there is a last frost after February 15 be ready to cover your astilbe in the event of a late frost.

USDA Zone Info for Fairfax

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 Fairfax

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