One of the best tools that you have as gardeners to help us figure out your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In Sonora you can figure out when you can plant lemon balm 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 are one of those plants that can tolerate a tiny bit of cold weather.

The earliest that you can plant lemon balm in Sonora 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. Any later than that and your lemon balm may not have a chance to fully mature. If you are starting your lemon balm indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

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

Just be sure to remember that USDA zone info for Sonora 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 Sonora last frost occurs after February 15 be ready to protect your lemon balm in the event of a surprise late frost.

USDA Zone Info for Sonora

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 Sonora

You may be interested in your other planting guides for Sonora.