One of the first steps you take when you are estimating 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 figuring out when it's a good idea to plant ageratum is to check out the USDA zone info for Harvard.

Planting Calendar for Ageratum

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

Ageratum are not cold tolerant which means that you have to wait until it warms up after the last frost before you can plant them.

The earliest that you can plant ageratum in Harvard 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

In Harvard the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

Remember that USDA zone info for Harvard is an average and the actual date of last frost is different every year. Half of the time in Harvard you get a frost after April 15 so just be sure to be ready to protect your ageratum in the event of a late frost.

USDA Zone Info for Harvard

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 Harvard

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