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 first opportunity to plant heliotrope in Duncan should be figured out by using the USDA zone info.

Planting Calendar for Heliotrope

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

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

The earliest that you can plant heliotrope in Duncan 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. Any later than that and your heliotrope may not have a chance to fully mature. If you are starting your heliotrope indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

In Duncan the average date of last frost happens on April 15. You should expect an average low temperature of 5°F in the coldest months of winter.

It's important to remember that USDA zone info for Duncan is an average and the actual date of last frost changes from year to year. Since half of the time in Duncan you get surprised by a frost after April 15 be ready to cover your heliotrope in the event of a late frost.

USDA Zone Info for Duncan

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Duncan

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