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

You should be able to figure out when it's possible to plant ageratum by using the USDA zone info for Ishpeming.

Planting Calendar for Ageratum

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

It's a bad idea to plant ageratum until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant ageratum in Ishpeming 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 grow to maturity. You can get started a little bit earlier by starting your ageratum indoors.

Last Frost Date

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

Always keep in mind that USDA zone info for Ishpeming may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in Ishpeming it frosts late in the year after May 15 be ready to cover your ageratum if you have one of those late frosts.

USDA Zone Info for Ishpeming

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 Ishpeming

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