When to Plant Purple Rock Cress in Olney, IL

Before planting it is a good idea to find your USDA Zone info to figure out 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.

By using the USDA zone info for Olney you should be able to estimate when you can plant purple rock cress.


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 tend to make it in cold weather which tells us that you can plant them earlier in the year 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 Olney 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 fully mature. If you are starting your purple rock cress indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Olney. In the coldest months of winter you can expect an average low temperature of -10°F.

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 Olney and it will vary from year to year. Half of the time in Olney there is a last frost after April 15 so make sure that you are ready to cover your purple rock cress if you have a surprise late frost.

USDA Zone Info for Olney

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-10°F
Highest Expected Low-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Olney

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