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.

You will be able to determine when you can plant astilbe by checking out the USDA zone info for Signal Mountain.

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 tend to make it in mild cold which tells us that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant astilbe in Signal Mountain 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 astilbe and expect a good harvest is probably August. 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 little bit earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Signal Mountain. You should expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Signal Mountain may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Signal Mountain you get a frost after April 15 be ready to cover your astilbe if you have one of those late frosts.

USDA Zone Info for Signal Mountain

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Signal Mountain

You may be interested in your other planting guides for Signal Mountain.