One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant ageratum in Highland Park 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 the last frost.

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

The earliest that you can plant ageratum in Highland Park 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 grow to maturity. If you are starting your ageratum indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Highland Park the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Highland Park is just an average the actual date of last frost will vary from year to year. Since half of the time in Highland Park last frost occurs after April 15 be ready to protect your ageratum in the event of a surprise late frost.

USDA Zone Info for Highland Park

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 Highland Park

You may be interested in your other planting guides for Highland Park.