The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Oak Park you can estimate when you can plant heliotrope by referring to the USDA zone info.

Planting Calendar for Heliotrope

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

Heliotrope require warm weather which tells us that you have to wait until it warms up after the last frost has passed before you can plant them.

The earliest that you can plant heliotrope in Oak 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 heliotrope and expect a good harvest is probably August. You probably don't want to wait any later than that or else your heliotrope may not have a chance to really do well. Starting your heliotrope indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Oak Park. It might get as low as -10°F during the coldest months of winter.

Since the USDA zone info for Oak Park is not always accurate the actual date of last frost changes from year to year. Half of the time in Oak Park you get surprised by a frost after April 15 so be sure to be ready to cover your heliotrope if you have one of those late frosts.

USDA Zone Info for Oak Park

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 Oak Park

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