One of the first steps you take when you are getting a good idea 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.

A way of estimating when it's the best time to plant watercress is to look at the USDA zone info for Zone 1b.

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 well in some cold which means that you can plant them just a tiny bit earlier in the year than other frost tender plants.

The earliest that you can plant watercress in Zone 1b is June. However, you really should wait until July if you don't want to take any chances.

The last month that you can plant watercress and expect a good harvest is probably July. You probably don't want to wait any later than that or else your watercress may not have a chance to really do well. Starting your watercress indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Zone 1b the average date of last frost happens on June 15. In the coldest months of winter you can expect an average low temperature of -55°F.

Remember that the actual date of last frost is an average because it is based on the USDA zone info for Zone 1b and it changes from year to year. Since half of the time in Zone 1b you get a frost after June 15 be ready to cover your watercress if you have a late frost.

USDA Zone Info for Zone 1b

Here is the info for USDA Zone 1b.

Average Date of Last Frost (spring)	June 15
Average Date of First Frost (fall)	July 15
Lowest Expected Low	-55°F
Highest Expected Low	-50°F

This means that on a really cold year, the coldest it will get is -55°F. On most years you should be prepared to experience lows near -50°F.

Plants to Grow in Zone 1b

You may be interested in your other planting guides for Zone 1b.