Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant ageratum in Zone 5b should 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 the last frost when the weather gets warmer.

It's probably a bad idea to plant ageratum until after the last frost because they do not do well in cold weather.

The earliest that you can plant ageratum in Zone 5b 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. 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 couple of weeks earlier by starting your ageratum indoors.

Last Frost Date

The average date of last frost is April 15 in Zone 5b. You should expect an average low temperature of -15°F in the coldest months of winter.

It's important to remember that USDA zone info for Zone 5b is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Zone 5b last frost occurs after April 15 so always be ready to protect your ageratum in the event of one of those late frosts.

USDA Zone Info for Zone 5b

Here is the info for USDA Zone 5b.

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

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Zone 5b

You may be interested in your other planting guides for Zone 5b.