One of the first steps you take when you are getting a good idea your gardening schedule is find your 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.

A way of getting a good idea when it's possible to plant ageratum is to check out the USDA zone info for Duluth.

Planting Calendar for Ageratum

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

Since ageratum do not do well in cold weather it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant ageratum in Duluth 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 fully mature. You can get started a few weeks earlier by starting your ageratum indoors.

Last Frost Date

In Duluth the average date of last frost happens on May 15. It might get as low as -30°F during the coldest months of winter.

Always keep in mind that USDA zone info for Duluth may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Half of the time in Duluth you get surprised by a frost after May 15 so make sure that you are prepared to protect your ageratum in the event of one of those late frosts.

USDA Zone Info for Duluth

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 Duluth

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