The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Sioux Falls should be used to figure out when it's the best time 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.

Astilbe do ok in a tiny bit of cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant astilbe in Sioux Falls 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 grow to maturity. You can get started a couple of weeks earlier by starting your astilbe indoors.

Last Frost Date

On average the last frost is on May 15 in Sioux Falls. In the coldest months of winter you can expect an average low temperature of -25°F.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Sioux Falls and it is different every year. Since half of the time in Sioux Falls you get surprised by a frost after May 15 be ready to cover your astilbe if you have a surprise late frost.

USDA Zone Info for Sioux Falls

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 Sioux Falls

You may be interested in your other planting guides for Sioux Falls.