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

You should be able to estimate when it's a good idea to plant pentas by reviewing the USDA zone info for Portola Valley.

Planting Calendar for Pentas

Frost tolerance for pentas:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

You should not plant pentas until after all chance of frost has passed because they do not do well in cold weather.

The earliest that you can plant pentas 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 pentas and expect a good harvest is probably September. Any later than that and your pentas may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your pentas indoors.

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.

Always keep in mind that the actual date of last frost is an average 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 there is a last frost after January 31 be ready to cover your pentas in the event of 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.