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.

The earliest that you can plant roses in Portola Valley should be figured out by using the USDA zone info.

Planting Calendar for Roses

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

Since roses do well in moderate cold you can plant them just a bit earlier in the year than more sensitive plants.

The earliest that you can plant roses 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 roses and expect a good harvest is probably October. If you wait any later than that and your roses may not have a chance to grow to maturity. Starting your roses indoors is a great way to get them started a few weeks earlier.

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.

Always keep in mind that USDA zone info for Portola Valley is just an average and the actual date of last frost can change quite a bit 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 roses in the event of 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.