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.

You can determine when it's a good idea to plant lemon balm in San Francisco by using the USDA zone info.

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 slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant lemon balm in San Francisco 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 grow to maturity. 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 San Francisco. It might get as low as 35°F during the coldest months of winter.

Keep in mind that USDA zone info for San Francisco may not be accurate from year to year and the actual date of last frost is different every year. Since half of the time in San Francisco there is a last frost after January 31 be ready to protect your lemon balm if you have a surprise late frost.

USDA Zone Info for San Francisco

Here is the info for USDA Zone 10b.

Average Date of Last Frost (spring)	January 31
Average Date of First Frost (fall)	December 15
Lowest Expected Low	35°F
Highest Expected Low	40°F

This means that on a really cold year, the coldest it will get is 35°F. On most years you should be prepared to experience lows near 40°F.

Plants to Grow in San Francisco

You may be interested in your other planting guides for San Francisco.