One of the best tools that you have as gardeners to help us estimate 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.

You should be able to estimate when it's possible to plant heliotrope by looking at the USDA zone info for Evansville.

Planting Calendar for Heliotrope

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

Heliotrope do not do well in cold 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 Evansville 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. If you wait any later than that and your heliotrope may not have a chance to really do well. You can get started a few weeks earlier by starting your heliotrope indoors.

Last Frost Date

On average the last frost is on April 15 in Evansville. You should expect an average low temperature of -20°F in the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Evansville and it is different every year. Since half of the time in Evansville there is a last frost after April 15 be ready to protect your heliotrope if you have one of those late frosts.

USDA Zone Info for Evansville

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Evansville

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