The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You should be able to figure out when it's possible to plant oregano by using the USDA zone info for Portola Valley.

Planting Calendar for Oregano

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

Since oregano are moderately cold tolerant you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant oregano 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 oregano and expect a good harvest is probably October. You probably don't want to wait any later than that or else your oregano may not have a chance to fully mature. Starting your oregano indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost is on January 31 in Portola Valley. You can expect an average low temperature of 30°F in the coldest months of winter.

Keep in mind that USDA zone info for Portola Valley is just an average and the actual date of last frost is different every year. Since half of the time in Portola Valley you get a frost after January 31 be ready to protect your oregano if you have a late frost.

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.