Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The best time to plant rock cress in International Falls can be estimated 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 International Falls 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. You can get started a little bit earlier by starting your rock cress indoors.

Last Frost Date

On average the last frost is on May 15 in International Falls. It might get as low as -40°F during the coldest months of winter.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for International Falls and it can change quite a bit from year to year. Half of the time in International Falls you get a frost after May 15 so be sure to be ready to cover your rock cress if you have a late frost.

USDA Zone Info for International Falls

Here is the info for USDA Zone 3a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-40°F
Highest Expected Low	-35°F

This means that on a really cold year, the coldest it will get is -40°F. On most years you should be prepared to experience lows near -35°F.

Plants to Grow in International Falls

You may be interested in your other planting guides for International Falls.