When can I plant Astilbe in Zone 2a

One of the first steps we take when we are determining our gardening schedule is find our USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for our area.

The USDA zone info for Zone 2a should be reffered to in order to estimate when to plant astilbe.


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.

Since astilbe are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year 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 2a is May. However, you really should wait until June 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 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 May 15 in Zone 2a. We can expect an average low temperature of -50°F in the coldest months of winter.

It's important to remember that USDA zone info for Zone 2a is an average and our actual date of last frost can change quite a bit from year to year. Half of the time in Zone 2a there is a last frost after May 15 so just be sure to be ready to cover your astilbe in the event of one of those late frosts.

USDA Zone Info for Zone 2a

Here is the info for USDA Zone 2a.

Average Date of Last Frost (spring)May 15
Average Date of First Frost (fall)August 15
Lowest Expected Low-50°F
Highest Expected Low-45°F

This means that on a really cold year, the coldest it will get is -50°F. On most years you should be prepared to experience lows near -45°F.

Plants to Grow in Zone 2a

You may be interested in our other planting guides for Zone 2a.