The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

It's possible to figure out when you can plant watercress by using the USDA zone info for Hayward.

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 can survive in mild cold which means that you can plant them slightly earlier in the year than other frost tender plants.

The earliest that you can plant watercress in Hayward 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 fully mature. If you are starting your watercress indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Hayward. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Hayward is just an average the actual date of last frost is different every year. Since half of the time in Hayward you get surprised by a frost after January 31 be ready to cover your watercress in the event of a late frost.

USDA Zone Info for Hayward

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 Hayward

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