One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

One way of getting a good idea when it's the best time to plant watercress is to consult the USDA zone info for Manassas.

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 a tiny bit of cold which tells us that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant watercress in Manassas 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. If you are starting your watercress indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Manassas. You can expect an average low temperature of 0°F in the coldest months of winter.

Since the USDA zone info for Manassas is just an average the actual date of last frost changes from year to year. Half of the time in Manassas it frosts late in the year after April 15 so always be ready to cover your watercress in the event of one of those late frosts.

USDA Zone Info for Manassas

Here is the info for USDA Zone 7a.

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

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

Plants to Grow in Manassas

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