One of the first steps you take when you are figuring out your gardening schedule is find your 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.

You can estimate when it's possible to plant watercress in Willmar by checking out the USDA zone info.

Planting Calendar for Watercress

Frost tolerance for watercress:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant watercress slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant watercress in Willmar is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant watercress and expect a good harvest is probably August. Any later than that and your watercress may not have a chance to fully mature. Starting your watercress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Willmar the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Willmar and it will vary from year to year. Half of the time in Willmar you get a frost after May 15 so just be sure to be ready to cover your watercress if you have a surprise late frost.

USDA Zone Info for Willmar

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 Willmar

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