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.

By looking at the USDA zone info for Napa it's possible to estimate when you can plant mustard greens.

Planting Calendar for Mustard greens

Frost tolerance for mustard greens:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Mustard greens do well in moderate cold which means that you can get them planted earlier than other plants that might not handle the cold.

The earliest that you can plant mustard greens in Napa is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant mustard greens and expect a good harvest is probably October. Any later than that and your mustard greens may not have a chance to fully mature. Starting your mustard greens indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average all chance of frost has passed is on February 15 in Napa. You should expect an average low temperature of 25°F in the coldest months of winter.

Always keep in mind that USDA zone info for Napa is just an average and the actual date of last frost changes from year to year. Since half of the time in Napa last frost occurs after February 15 be ready to protect your mustard greens in the event of a late frost.

USDA Zone Info for Napa

Here is the info for USDA Zone 9b.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	25°F
Highest Expected Low	30°F

This means that on a really cold year, the coldest it will get is 25°F. On most years you should be prepared to experience lows near 30°F.

Plants to Grow in Napa

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