The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's the best time to plant watercress is to check out the USDA zone info for Pacific.

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 are barely cold tolerant which means that you can get them planted just a bit earlier than other frost tender plants.

The earliest that you can plant watercress in Pacific 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 fully mature. If you are starting your watercress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on April 15 in Pacific. You can expect an average low temperature of -10°F in the coldest months of winter.

Keep in mind that USDA zone info for Pacific is an average and the actual date of last frost can change quite a bit from year to year. Half of the time in Pacific last frost occurs after April 15 so make sure that you are ready to cover your watercress in the event of a surprise late frost.

USDA Zone Info for Pacific

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 Pacific

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