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When to Plant Purple Rock Cress in Wilmette, IL

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The first opportunity to plant purple rock cress in Wilmette can be determined by looking at 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.

Since purple rock cress are one of those plants that can tolerate quite a bit of cold weather you can plant them quite a bit earlier in the year than plants that are more sensitive to 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 Wilmette 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. 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 Wilmette. You can expect an average low temperature of -15°F in the coldest months of winter.

Always keep in mind 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 Wilmette and it can change quite a bit from year to year. Half of the time in Wilmette last frost occurs after April 15 so always be ready to cover your purple rock cress in the event of one of those late frosts.

USDA Zone Info for Wilmette

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 Wilmette

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