One of the first steps you take when you are estimating your gardening schedule is find your USDA Zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

It's a good idea to estimate when it's a good idea to plant lemon balm by reviewing the USDA zone info for Billings.

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 tend to make it in very little cold which tells us that you can plant them a bit earlier in the year than other frost tender plants.

The earliest that you can plant lemon balm in Billings is April. However, you really should wait until May 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. Any later than that and your lemon balm may not have a chance to fully mature. Starting your lemon balm indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

The average date of last frost is May 15 in Billings. It might get as low as -25°F during the coldest months of winter.

Keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Billings and it can change quite a bit from year to year. Since half of the time in Billings there is a last frost after May 15 be ready to protect your lemon balm if you have a surprise late frost.

USDA Zone Info for Billings

Here is the info for USDA Zone 4b.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-25°F
Highest Expected Low	-20°F

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

Plants to Grow in Billings

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