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.

The best time to plant rhubarb in Portola Valley can be determined by checking out the USDA zone info.

Planting Calendar for Rhubarb

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

You can plant rhubarb a bit earlier in the year because they do well in moderate cold.

The earliest that you can plant rhubarb 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 rhubarb and expect a good harvest is probably October. If you wait any later than that and your rhubarb may not have a chance to grow to maturity. If you are starting your rhubarb indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

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

Just be sure to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Portola Valley and it can change quite a bit from year to year. Since half of the time in Portola Valley there is a last frost after January 31 be ready to cover your rhubarb 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.