One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portola Valley you can estimate when it's possible to plant mustard greens by checking out the USDA zone info.

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 Portola Valley 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 couple of weeks earlier.

Last Frost Date

The average date of last frost is January 31 in Portola Valley. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Portola Valley is not always accurate the actual date of last frost will vary from year to year. Half of the time in Portola Valley you get a frost after January 31 so make sure that you are prepared to cover your mustard greens in the event of one of those late frosts.

USDA Zone Info for Portola Valley

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 Portola Valley

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