One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of making a decision about when it's possible to plant heliotrope is to consult the USDA zone info for Blackfoot.

Planting Calendar for Heliotrope

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

It's not a good idea to plant heliotrope until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant heliotrope in Blackfoot 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. Starting your heliotrope indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Blackfoot. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Blackfoot may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Since half of the time in Blackfoot you get a frost after April 15 be ready to protect your heliotrope if you have a late frost.

USDA Zone Info for Blackfoot

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 Blackfoot

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