One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when you can plant watercress in Grass Valley 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 just a tiny 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 Grass Valley 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 grow to maturity. You can get started a few weeks earlier by starting your watercress indoors.

Last Frost Date

On average the last frost has passed is on February 15 in Grass Valley. In the coldest months of winter you can expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost is an average because it is based on the USDA zone info for Grass Valley and it is different every year. Half of the time in Grass Valley you get a frost after February 15 so just be sure to be ready to cover your watercress in the event of one of those late frosts.

USDA Zone Info for Grass Valley

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Grass Valley

You may be interested in your other planting guides for Grass Valley.