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

By reviewing the USDA zone info for Zimmerman it's a good idea to estimate when it's a good idea to plant ageratum.

Planting Calendar for Ageratum

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

Ageratum require warm weather which means that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant ageratum in Zimmerman 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. If you wait any later than that and your ageratum may not have a chance to grow to maturity. Starting your ageratum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Zimmerman the average date of last frost happens on May 15. You should expect an average low temperature of -30°F in the coldest months of winter.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Zimmerman and it can change quite a bit from year to year. Since half of the time in Zimmerman you get surprised by a frost after May 15 be ready to cover your ageratum in the event of one of those late frosts.

USDA Zone Info for Zimmerman

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Zimmerman

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