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.

In Barnwell you can estimate when it's possible to plant watercress by reviewing 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.

Watercress do ok in some cold which means that you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant watercress in Barnwell 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 grow to maturity. You can get started a little bit earlier by starting your watercress indoors.

Last Frost Date

On average the last frost is on March 15 in Barnwell. In the coldest months of winter you should expect an average low temperature of 10°F.

Since the USDA zone info for Barnwell is not always accurate the actual date of last frost changes from year to year. Since half of the time in Barnwell you get surprised by a frost after March 15 be ready to protect your watercress in the event of a surprise late frost.

USDA Zone Info for Barnwell

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in Barnwell

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