Before planting it is a good idea to find your USDA Zone info to determine your garden 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 Sun Prairie can be used to figure out when it's possible to plant ageratum.

Planting Calendar for Ageratum

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

Since ageratum are not cold tolerant it's important to wait until after the last frost before you can plant them.

The earliest that you can plant ageratum in Sun Prairie 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 ageratum and expect a good harvest is probably August. You probably don't want to wait any later than that or else your ageratum may not have a chance to fully mature. Starting your ageratum indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Sun Prairie the average date of last frost happens on April 15. You should expect an average low temperature of -20°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Sun Prairie and it changes from year to year. Since half of the time in Sun Prairie there is a last frost after April 15 be ready to protect your ageratum if you have one of those late frosts.

USDA Zone Info for Sun Prairie

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Sun Prairie

You may be interested in your other planting guides for Sun Prairie.