One of the first steps you take when you are determining your gardening schedule is find your 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.

In Port Huron you can determine when it's possible to plant purple rock cress by checking out the USDA zone info.

Planting Calendar for Purple Rock Cress

Frost tolerance for purple rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant purple rock cress quite a bit earlier in the year because they do well in cold.

The earliest that you can plant purple rock cress in Port Huron is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant purple rock cress and expect a good harvest is probably September. Any later than that and your purple rock cress may not have a chance to really do well. You can get started a little bit earlier by starting your purple rock cress indoors.

Last Frost Date

In Port Huron the average date of last frost happens on April 15. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Port Huron is not always accurate the actual date of last frost can change quite a bit from year to year. Half of the time in Port Huron it frosts late in the year after April 15 so make sure that you are ready to cover your purple rock cress if you have a surprise late frost.

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.