When to Plant Purple Rock Cress in Northbrook, IL

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.

The first chance to plant purple rock cress in Northbrook should be figured out by reviewing 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.

Purple Rock Cress are one of those plants that can tolerate quite a bit of cold weather which means that you can start planting them much earlier than other plants that might not handle the cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant purple rock cress
Possibly ok, but a risky time to plant purple rock cress
Probably not a good time to plant purple rock cress

The earliest that you can plant purple rock cress in Northbrook 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 really do well. You can get started a little bit earlier by starting your purple rock cress indoors.

Last Frost Date

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

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Northbrook and it is different every year. Since half of the time in Northbrook you get a frost after April 15 be ready to protect your purple rock cress in the event of a late frost.

USDA Zone Info for Northbrook

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 Northbrook

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