One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. 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 Pierre can be reffered to in order to determine when you can plant heliotrope.

Planting Calendar for Heliotrope

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

It's probably a bad idea to plant heliotrope until after the last frost has passed because they require warm weather.

The earliest that you can plant heliotrope in Pierre is May. However, you really should wait until June 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. You can get started a couple of weeks earlier by starting your heliotrope indoors.

Last Frost Date

On average the last frost is on May 15 in Pierre. In the coldest months of winter you can expect an average low temperature of -25°F.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Pierre and it will vary from year to year. Since half of the time in Pierre you get surprised by a frost after May 15 be ready to protect your heliotrope in the event of one of those late frosts.

USDA Zone Info for Pierre

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Pierre

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