Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Ankeny you can figure out when to plant rock cress by looking at the USDA zone info.

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 much earlier in the year because they are very cold tolerant.

The earliest that you can plant rock cress in Ankeny 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. 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 Ankeny. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Ankeny may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Ankeny you get a frost after April 15 be ready to cover your rock cress if you have a surprise late frost.

USDA Zone Info for Ankeny

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-20°F
Highest Expected Low	-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Ankeny

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