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

The USDA zone info for Oak Brook can be read to estimate when to plant ageratum.

Planting Calendar for Ageratum

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

Since ageratum require warm weather it's necessary to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant ageratum in Oak Brook 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 really do well. Starting your ageratum indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Oak Brook. It might get as low as -15°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Oak Brook and it changes from year to year. Half of the time in Oak Brook you get surprised by a frost after April 15 so just be sure to be ready to cover your ageratum in the event of a late frost.

USDA Zone Info for Oak Brook

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 Oak Brook

You may be interested in your other planting guides for Oak Brook.