One of the first steps you take when you are figuring out 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 La Mesa can be used to determine when you can 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.

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 La Mesa is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant watercress and expect a good harvest is probably September. 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 little bit earlier.

Last Frost Date

In La Mesa the average date of last frost happens on January 31. You can expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for La Mesa is an average the actual date of last frost will vary from year to year. Half of the time in La Mesa you get a frost after January 31 so be sure to be ready to cover your watercress in the event of a late frost.

USDA Zone Info for La Mesa

Here is the info for USDA Zone 10a.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	30°F
Highest Expected Low	35°F

This means that on a really cold year, the coldest it will get is 30°F. On most years you should be prepared to experience lows near 35°F.

Plants to Grow in La Mesa

You may be interested in your other planting guides for La Mesa.