The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Spearfish you can estimate when it's possible to plant heliotrope 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.

Heliotrope do not do well in cold weather which tells us that it's important 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 Spearfish 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 really do well. Starting your heliotrope indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

It's important to remember that USDA zone info for Spearfish is not always accurate and the actual date of last frost changes from year to year. Since half of the time in Spearfish you get surprised by a frost after April 15 be ready to cover your heliotrope in the event of a surprise late frost.

USDA Zone Info for Spearfish

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 Spearfish

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