One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Detroit Lakes you can estimate when it's possible to plant ageratum by checking out the USDA zone info.

Planting Calendar for Ageratum

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

You can not plant ageratum until after the last frost has passed because they are not cold tolerant.

The earliest that you can plant ageratum in Detroit Lakes 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 really do well. Starting your ageratum indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Detroit Lakes. It might get as low as -35°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Detroit Lakes and it can change quite a bit from year to year. Since half of the time in Detroit Lakes 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 Detroit Lakes

Here is the info for USDA Zone 3b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-35°F
Highest Expected Low	-30°F

This means that on a really cold year, the coldest it will get is -35°F. On most years you should be prepared to experience lows near -30°F.

Plants to Grow in Detroit Lakes

You may be interested in your other planting guides for Detroit Lakes.