One of the first steps you take when you are determining your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Stillwater you can determine when it's possible to plant rock cress by using 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.

Rock Cress are very cold tolerant which tells us that you can plant them much earlier than more sensitive plants.

The earliest that you can plant rock cress in Stillwater 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 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 May 15 in Stillwater. In the coldest months of winter you can expect an average low temperature of -25°F.

Since the USDA zone info for Stillwater is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Stillwater last frost occurs after May 15 be ready to protect your rock cress in the event of one of those late frosts.

USDA Zone Info for Stillwater

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 Stillwater

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