One of the best tools that you have as gardeners to help us determine 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.

The USDA zone info for Winona can be reffered to in order to determine when it's possible 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.

You can plant rock cress 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 Winona is March. However, you really should wait until April 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 August. Any later than that and your rock cress may not have a chance to grow to maturity. 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

In Winona the average date of last frost happens on May 15. You should expect an average low temperature of -25°F in the coldest months of winter.

Since the USDA zone info for Winona is an average the actual date of last frost will vary from year to year. Since half of the time in Winona last frost occurs after May 15 be ready to cover your rock cress in the event of a surprise late frost.

USDA Zone Info for Winona

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

This means that on a really cold year, the coldest it will get is -25°F. On most years you should be prepared to experience lows near -20°F.

Plants to Grow in Winona

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