One of the best tools that you have as gardeners to help us estimate 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.

The USDA zone info for Rock Falls should be used to determine when 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 are barely cold tolerant which tells us that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant lemon balm in Rock Falls 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. Any later than that and your lemon balm may not have a chance to fully mature. You can get started a couple of weeks earlier by starting your lemon balm indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Rock Falls. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Rock Falls may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Rock Falls you get a frost after April 15 so make sure that you are ready to protect your lemon balm in the event of a late frost.

USDA Zone Info for Rock Falls

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-15°F
Highest Expected Low	-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in Rock Falls

You may be interested in your other planting guides for Rock Falls.