Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The best time to plant watercress in San Marcos should be figured out by referring to 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.

You can plant watercress a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant watercress in San Marcos 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. If you wait any later than that and your watercress may not have a chance to really do well. Starting your watercress indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in San Marcos. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for San Marcos may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in San Marcos it frosts late in the year after January 31 so always be ready to protect your watercress in the event of one of those late frosts.

USDA Zone Info for San Marcos

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 San Marcos

You may be interested in your other planting guides for San Marcos.