Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant lemon balm in Walla Walla should be estimated by looking at 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.

Lemon balm are one of those plants that can tolerate a tiny bit of cold weather which tells us that you can plant them slightly earlier than more sensitive plants.

The earliest that you can plant lemon balm in Walla Walla is March. However, you really should wait until April 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 August. If you wait any later than that and your lemon balm may not have a chance to fully mature. You can get started a few weeks earlier by starting your lemon balm indoors.

Last Frost Date

The average date of last frost is April 15 in Walla Walla. It might get as low as 0°F during the coldest months of winter.

Since the USDA zone info for Walla Walla is not always accurate the actual date of last frost changes from year to year. Since half of the time in Walla Walla you get surprised by a frost after April 15 be ready to cover your lemon balm if you have a surprise late frost.

USDA Zone Info for Walla Walla

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Walla Walla

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