The USDA Zone info is a great tool for gardeners to help us figure out 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.

A way of getting a good idea when you can plant twinspur is to use the USDA zone info for Portola Valley.

Planting Calendar for Twinspur

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

Twinspur do well in moderate cold which tells us that you can plant them a bit earlier in the year than other plants that might not handle the cold.

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

Last Frost Date

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

Since the USDA zone info for Portola Valley is not always accurate the actual date of last frost is different every year. Since half of the time in Portola Valley last frost occurs after January 31 be ready to cover your twinspur if you have 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.