One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can figure out when it's a good idea to plant watercress in Cambridge by looking at 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 are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant watercress in Cambridge 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. You probably don't want to wait any later than that or else your watercress may not have a chance to fully mature. You can get started a little bit earlier by starting your watercress indoors.

Last Frost Date

The average date of last frost is April 15 in Cambridge. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that USDA zone info for Cambridge is an average and the actual date of last frost will vary from year to year. Half of the time in Cambridge it frosts late in the year after April 15 so make sure that you are prepared to cover your watercress in the event of a late frost.

USDA Zone Info for Cambridge

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Cambridge

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