One of the first steps you take when you are determining 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.

It's a good idea to figure out when it's possible to plant heliotrope by using the USDA zone info for Portola Valley.

Planting Calendar for Heliotrope

Frost tolerance for heliotrope:	Not tolerant of frost.
When to plant:	After the last frost.

Since heliotrope require warm weather you have to wait until after the last frost before you can plant them.

The earliest that you can plant heliotrope 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 heliotrope and expect a good harvest is probably September. You probably don't want to wait any later than that or else your heliotrope may not have a chance to fully mature. Starting your heliotrope indoors is a great way to get them started a little bit earlier.

Last Frost Date

The average date of last frost is January 31 in Portola Valley. It might get as low as 30°F during the coldest months of winter.

Since the USDA zone info for Portola Valley may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Portola Valley you get a frost after January 31 so always be ready to cover your heliotrope 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.