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.

One way of figuring out when you can plant watercress is to consult the USDA zone info for Thurmont.

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.

Since watercress are barely cold tolerant 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 Thurmont 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. If you wait 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 little bit earlier.

Last Frost Date

In Thurmont the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -5°F.

Since the USDA zone info for Thurmont is not always accurate the actual date of last frost will vary from year to year. Half of the time in Thurmont you get surprised by a frost after April 15 so just be sure to be ready to cover your watercress if you have a surprise late frost.

USDA Zone Info for Thurmont

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Thurmont

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