Before planting it is a good idea to find your USDA Zone info to determine 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 USDA zone info for South Beloit can be looked at to estimate when it's a good idea 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 do ok in moderate cold which tells us that you can plant them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant watercress in South Beloit 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 watercress and expect a good harvest is probably August. Any later than that and your watercress may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your watercress indoors.

Last Frost Date

On average the last frost has passed is on April 15 in South Beloit. In the coldest months of winter you can expect an average low temperature of -15°F.

Just be sure to remember that USDA zone info for South Beloit is an average and the actual date of last frost is different every year. Since half of the time in South Beloit there is a last frost after April 15 be ready to cover your watercress in the event of a surprise late frost.

USDA Zone Info for South Beloit

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in South Beloit

You may be interested in your other planting guides for South Beloit.