One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You will be able to figure out when it's the best time to plant ageratum by using the USDA zone info for Lake Elmo.

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 has passed before you can plant them.

The earliest that you can plant ageratum in Lake Elmo 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. You probably don't want to wait any later than that or else your ageratum may not have a chance to really do well. If you are starting your ageratum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Lake Elmo. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Lake Elmo is just an average the actual date of last frost will vary from year to year. Since half of the time in Lake Elmo last frost occurs after May 15 be ready to cover your ageratum if you have a late frost.

USDA Zone Info for Lake Elmo

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 Lake Elmo

You may be interested in your other planting guides for Lake Elmo.