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

It's possible to estimate when it's a good idea to plant heliotrope by referring to the USDA zone info for Glen Ellyn.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

Since heliotrope are not cold tolerant it is necessary to wait until after the last frost before you can plant them.

The earliest that you can plant heliotrope in Glen Ellyn 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 grow to maturity. If you are starting your heliotrope indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Glen Ellyn. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for Glen Ellyn and it will vary from year to year. Half of the time in Glen Ellyn you get surprised by a frost after April 15 so make sure that you are prepared to cover your heliotrope in the event of a late frost.

USDA Zone Info for Glen Ellyn

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 Glen Ellyn

You may be interested in your other planting guides for Glen Ellyn.