The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Port Huron you can determine when you can plant heliotrope by referring to the USDA zone info.

Planting Calendar for Heliotrope

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

Since heliotrope are not cold tolerant you must wait until after the last frost has passed before you can plant them.

The earliest that you can plant heliotrope in Port Huron 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. You probably don't want to wait any later than that or else your heliotrope may not have a chance to really do well. 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

The average date of last frost is April 15 in Port Huron. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Port Huron is an average the actual date of last frost changes from year to year. Since half of the time in Port Huron you get a frost after April 15 be ready to cover your heliotrope if you have one of those late frosts.

USDA Zone Info for Port Huron

Here is the info for USDA Zone 6a.

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

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

Plants to Grow in Port Huron

You may be interested in your other planting guides for Port Huron.