Before planting it is a good idea to find your USDA Zone info to determine 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 possible to determine when you can plant purple rock cress by using the USDA zone info for Mchenry.

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.

Purple Rock Cress are very cold tolerant which means that you can plant them a quite a bit earlier than other plants that might not handle the cold.

The earliest that you can plant purple rock cress in Mchenry 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 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

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

Since the USDA zone info for Mchenry is not always accurate the actual date of last frost will vary from year to year. Half of the time in Mchenry 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 Mchenry

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 Mchenry

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