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 liatris in Portola Valley should be figured out by referring to the USDA zone info.

Planting Calendar for Liatris

Frost tolerance for liatris:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

You can plant liatris much earlier in the year because they are very cold tolerant.

The earliest that you can plant liatris 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 liatris and expect a good harvest is probably October. Any later than that and your liatris may not have a chance to really do well. You can get started a few weeks earlier by starting your liatris indoors.

Last Frost Date

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

It's important to remember that USDA zone info for Portola Valley is an average and the actual date of last frost will vary from year to year. Half of the time in Portola Valley last frost occurs after January 31 so always be ready to protect your liatris 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.