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.

You can estimate when it's the best time to plant tritoma in Portola Valley by using the USDA zone info.

Planting Calendar for Tritoma

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

Since tritoma are one of those plants that can tolerate quite a bit of cold weather you can plant them much earlier in the year than more sensitive plants.

The earliest that you can plant tritoma 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 tritoma and expect a good harvest is probably October. If you wait any later than that and your tritoma may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your tritoma indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on January 31 in Portola Valley. You should expect an average low temperature of 30°F in the coldest months of winter.

Since the USDA zone info for Portola Valley is an average the actual date of last frost will vary from year to year. Half of the time in Portola Valley there is a last frost after January 31 so make sure that you are prepared to protect your tritoma in the event of a 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.