One of the best tools that you have as gardeners to help us estimate 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.

The earliest that you can plant ageratum in Ann Arbor can be determined by referring to the USDA zone info.

Planting Calendar for Ageratum

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

Ageratum are not cold tolerant which means that you really should wait until it warms up after all chance of frost has passed before you can plant them.

The earliest that you can plant ageratum in Ann Arbor is April. However, you really should wait until May 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

On average the last frost has passed is on April 15 in Ann Arbor. It might get as low as -10°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Ann Arbor may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in Ann Arbor you get a frost after April 15 be ready to protect your ageratum if you have a late frost.

USDA Zone Info for Ann Arbor

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Ann Arbor

You may be interested in your other planting guides for Ann Arbor.