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.

One way of estimating when it's a good idea to plant rock cress is to consult the USDA zone info for Detroit.

Planting Calendar for Rock Cress

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

You can plant rock cress quite a bit earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

The earliest that you can plant rock cress in Detroit 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 rock cress and expect a good harvest is probably September. You probably don't want to wait any later than that or else your rock cress may not have a chance to grow to maturity. Starting your rock cress indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Detroit the average date of last frost happens on April 15. It might get as low as -5°F during the coldest months of winter.

Since the USDA zone info for Detroit is not always accurate the actual date of last frost will vary from year to year. Half of the time in Detroit it frosts late in the year after April 15 so always be ready to cover your rock cress if you have a surprise late frost.

USDA Zone Info for Detroit

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Detroit

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