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 USDA zone info for San Diego can be reviewed to estimate 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.

Lemon balm do ok in moderate cold which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant lemon balm in San Diego 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. You can get started a few weeks earlier by starting your lemon balm indoors.

Last Frost Date

In San Diego the average date of last frost happens on February 15. In the coldest months of winter you should expect an average low temperature of 20°F.

It's important to remember that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for San Diego and it changes from year to year. Half of the time in San Diego there is a last frost after February 15 so be sure to be ready to cover your lemon balm in the event of a late frost.

USDA Zone Info for San Diego

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in San Diego

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