One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Portola Valley you can estimate when it's a good idea to plant streptocarpella by using the USDA zone info.

Planting Calendar for Streptocarpella

Frost tolerance for streptocarpella:	Not tolerant of frost.
When to plant:	After the last frost has passed.

Since streptocarpella require warm weather it is important to wait until after the last frost when the weather gets warmer before you can plant them.

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

Last Frost Date

On average all chance of frost has passed is on January 31 in Portola Valley. It might get as low as 30°F during the coldest months of winter.

Just be sure to remember that USDA zone info for Portola Valley is just an average and the actual date of last frost 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 streptocarpella if you have 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.