Before planting it is a good idea to find your USDA Zone info to estimate 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.

By referring to the USDA zone info for Sonoma it's a good idea to estimate when it's the best time to 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.

You can plant mustard greens just a bit earlier in the year because they are moderately cold tolerant.

The earliest that you can plant mustard greens in Sonoma 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. If you wait any later than that and your mustard greens may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your mustard greens indoors.

Last Frost Date

The average date of last frost is February 15 in Sonoma. It might get as low as 25°F during the coldest months of winter.

Since the USDA zone info for Sonoma is just an average the actual date of last frost is different every year. Half of the time in Sonoma you get surprised by a frost after February 15 so make sure that you are ready to protect your mustard greens in the event of one of those late frosts.

USDA Zone Info for Sonoma

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 Sonoma

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