One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to determine when you can plant ageratum by reviewing the USDA zone info for Tomah.

Planting Calendar for Ageratum

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

Ageratum do not do well in cold weather which tells us 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 Tomah 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 little bit earlier.

Last Frost Date

In Tomah the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Tomah is an average the actual date of last frost is different every year. Half of the time in Tomah you get surprised by a frost after May 15 so make sure that you are ready to protect your ageratum if you have a late frost.

USDA Zone Info for Tomah

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 Tomah

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