One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when you can plant rock cress is to look at the USDA zone info for Collinsville.

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 Collinsville 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. If you wait any later than that and your rock cress may not have a chance to really do well. If you are starting your rock cress indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

The average date of last frost is April 15 in Collinsville. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Collinsville is an average the actual date of last frost is different every year. Half of the time in Collinsville you get a frost after April 15 so make sure that you are ready to cover your rock cress in the event of a late frost.

USDA Zone Info for Collinsville

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Collinsville

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