One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The USDA zone info for Powell can be reviewed to figure out when it's possible to plant astilbe.

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.

You can plant astilbe just a tiny bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant astilbe in Powell is April. However, you really should wait until May 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. You can get started a few weeks earlier by starting your astilbe indoors.

Last Frost Date

The average date of last frost is May 15 in Powell. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Powell is just an average the actual date of last frost changes from year to year. Half of the time in Powell last frost occurs after May 15 so be sure to be ready to protect your astilbe if you have a surprise late frost.

USDA Zone Info for Powell

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°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 -20°F.

Plants to Grow in Powell

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