One of the first steps you take when you are getting a good idea your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Portola Valley it's a good idea to determine when it's the best time to plant lemon balm.

Planting Calendar for Lemon balm

Frost tolerance for lemon balm:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

You can plant lemon balm a bit earlier in the year because they are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant lemon balm 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 lemon balm and expect a good harvest is probably September. If you wait any later than that and your lemon balm may not have a chance to really do well. If you are starting your lemon balm indoors then you might be able to get away with starting them 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.

Remember that USDA zone info for Portola Valley may not be accurate from year to year and the actual date of last frost changes from year to year. Since half of the time in Portola Valley last frost occurs after January 31 be ready to protect your lemon balm if you have 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.