When can I plant Astilbe in Zone 6b

The USDA Zone info is a great tool for gardeners to help us figure out our gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for our area.

In Zone 6b you can determine when it's a good idea to plant astilbe by referring to the USDA zone info.


Planting Calendar for Astilbe

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

Astilbe are barely cold tolerant which means that you can plant them slightly earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant astilbe
Possibly ok, but a risky time to plant astilbe
Probably not a good time to plant astilbe

The earliest that you can plant astilbe in Zone 6b 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. Any later than that and 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

The average date of last frost is April 15 in Zone 6b. It might get as low as -5°F during the coldest months of winter.

Remember that our actual date of last frost is just an average because it is based on the USDA zone info for Zone 6b and it will vary from year to year. Half of the time in Zone 6b it frosts late in the year after April 15 so make sure that you are ready to protect your astilbe in the event of one of those late frosts.

USDA Zone Info for Zone 6b

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-5°F
Highest Expected Low0°F

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

Plants to Grow in Zone 6b

You may be interested in our other planting guides for Zone 6b.