One of the best tools that you have as gardeners to help us figure out your gardening schedule is the 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.

You can figure out when it's the best time to plant monarda in Billings by checking out the USDA zone info.

Planting Calendar for Monarda

Frost tolerance for monarda:	Tolerant of a very small amount of frost.
When to plant:	Up to 3 weeks before last frost.

Monarda do ok in moderate cold which means that you can plant them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant monarda 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 monarda and expect a good harvest is probably August. You probably don't want to wait any later than that or else your monarda may not have a chance to grow to maturity. You can get started a couple of weeks earlier by starting your monarda indoors.

Last Frost Date

On average the last frost has passed is on May 15 in Billings. In the coldest months of winter you should expect an average low temperature of -25°F.

Since the USDA zone info for Billings may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Billings it frosts late in the year after May 15 be ready to cover your monarda in the event of 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.