One of the first steps you take when you are determining 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.

The USDA zone info for Clearlake should be reviewed to determine when it's possible to plant watercress.

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 do ok in moderate cold 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 Clearlake 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. Starting your watercress indoors is a great way to get them started a little bit earlier.

Last Frost Date

In Clearlake the average date of last frost happens on March 15. You can expect an average low temperature of 15°F in the coldest months of winter.

Keep in mind that USDA zone info for Clearlake is not always accurate and the actual date of last frost will vary from year to year. Half of the time in Clearlake you get a frost after March 15 so always be ready to protect your watercress in the event of a late frost.

USDA Zone Info for Clearlake

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°F

This means that on a really cold year, the coldest it will get is 15°F. On most years you should be prepared to experience lows near 20°F.

Plants to Grow in Clearlake

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