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

By reviewing the USDA zone info for Portola Valley it's a good idea to figure out when it's a good idea to plant scarlet pimpernels.

Planting Calendar for Scarlet Pimpernels

Frost tolerance for scarlet pimpernels:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Since scarlet pimpernels are barely cold tolerant you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant scarlet pimpernels 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 scarlet pimpernels and expect a good harvest is probably September. Any later than that and your scarlet pimpernels may not have a chance to grow to maturity. Starting your scarlet pimpernels indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Portola Valley the average date of last frost happens on January 31. It might get as low as 30°F during the coldest months of winter.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Portola Valley and it changes from year to year. Since half of the time in Portola Valley it frosts late in the year after January 31 be ready to protect your scarlet pimpernels 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.