One of the first steps you take when you are making a decision about your gardening schedule is find your 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.

A common way of getting a good idea when it's possible to plant watercress is to refer to the USDA zone info for Ada.

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 slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant watercress in Ada 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. You can get started a couple of weeks earlier by starting your watercress indoors.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Ada and it will vary from year to year. Since half of the time in Ada last frost occurs after April 15 be ready to cover your watercress in the event of one of those late frosts.

USDA Zone Info for Ada

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 Ada

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