The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Elmhurst should be read to estimate when it's a good idea to plant rock cress.

Planting Calendar for Rock Cress

Frost tolerance for rock cress:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since rock cress are very cold tolerant you can plant them much earlier in the year than other frost tender plants.

The earliest that you can plant rock cress in Elmhurst 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. Any later than that and your rock cress may not have a chance to fully mature. Starting your 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 Elmhurst. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Elmhurst and it can change quite a bit from year to year. Half of the time in Elmhurst there is a last frost after April 15 so be sure to be ready to cover your rock cress in the event of a surprise late frost.

USDA Zone Info for Elmhurst

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 Elmhurst

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