Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's a good idea to figure out when you can plant purple rock cress by checking out the USDA zone info for Winthrop Harbor.

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 much earlier in the year because they are very cold tolerant.

The earliest that you can plant purple rock cress in Winthrop Harbor 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. If you wait any later than that and your purple rock cress may not have a chance to grow to maturity. Starting your purple rock cress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Winthrop Harbor the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Winthrop Harbor is an average and the actual date of last frost changes from year to year. Half of the time in Winthrop Harbor it frosts late in the year after April 15 so always be ready to cover your purple rock cress if you have a late frost.

USDA Zone Info for Winthrop Harbor

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 Winthrop Harbor

You may be interested in your other planting guides for Winthrop Harbor.