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 Viroqua can be looked at to figure out when it's a good idea 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 can survive in very little cold which tells us that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant astilbe in Viroqua 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. If you wait any later than that and 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 Viroqua. In the coldest months of winter you should expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Viroqua and it is different every year. Half of the time in Viroqua you get a frost after May 15 so just be sure to be ready to protect your astilbe in the event of a late frost.

USDA Zone Info for Viroqua

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 Viroqua

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