The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first chance to plant bidens in Portola Valley can be figured out by referring to the USDA zone info.

Planting Calendar for Bidens

Frost tolerance for bidens:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant bidens until after all chance of frost has passed because they are not cold tolerant.

The earliest that you can plant bidens in Portola Valley is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant bidens and expect a good harvest is probably September. You probably don't want to wait any later than that or else your bidens may not have a chance to fully mature. You can get started a little bit earlier by starting your bidens indoors.

Last Frost Date

On average the last frost is on 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 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 protect your bidens if you have a surprise 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.