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

It's possible to estimate when it's the best time to plant ageratum by looking at the USDA zone info for Viroqua.

Planting Calendar for Ageratum

Frost tolerance for ageratum:	Not tolerant of frost.
When to plant:	After the last frost.

Ageratum do not do well in cold weather which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant ageratum in Viroqua 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 ageratum and expect a good harvest is probably August. Any later than that and your ageratum may not have a chance to really do well. Starting your ageratum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average all chance of frost has passed is on May 15 in Viroqua. You should expect an average low temperature of -25°F in the coldest months of winter.

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 changes from year to year. Since half of the time in Viroqua it frosts late in the year after May 15 be ready to cover your ageratum 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.