One of the first steps you take when you are making a decision about 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.

The USDA zone info for New Ulm should be reviewed to figure out when it's the best time to plant watercress.

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.

Watercress are barely cold tolerant which tells us that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant watercress in New Ulm 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 really do well. You can get started a couple of weeks earlier by starting your watercress indoors.

Last Frost Date

The average date of last frost is May 15 in New Ulm. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for New Ulm may not be accurate from year to year the actual date of last frost will vary from year to year. Since half of the time in New Ulm you get a frost after May 15 be ready to cover your watercress in the event of a surprise late frost.

USDA Zone Info for New Ulm

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 New Ulm

You may be interested in your other planting guides for New Ulm.