Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Hawthorne should be used to estimate 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.

Since watercress are one of those plants that can tolerate a tiny bit of cold weather you can plant them just a tiny bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant watercress in Hawthorne 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. You can get started a few weeks earlier by starting your watercress indoors.

Last Frost Date

The average date of last frost is January 31 in Hawthorne. It might get as low as 35°F during the coldest months of winter.

Since the USDA zone info for Hawthorne is an average the actual date of last frost is different every year. Half of the time in Hawthorne you get surprised by a frost after January 31 so make sure that you are prepared to protect your watercress in the event of a surprise late frost.

USDA Zone Info for Hawthorne

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in Hawthorne

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