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 will be able to figure out when it's a good idea to plant pearl onions by checking out the USDA zone info for Miles City.

Planting Calendar for Pearl onions

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

Pearl onions do ok in moderate cold which tells us that you can start planting them slightly earlier than plants that are more sensitive to the cold.

The earliest that you can plant pearl onions in Miles City 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 pearl onions and expect a good harvest is probably August. Any later than that and your pearl onions may not have a chance to fully mature. If you are starting your pearl onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Miles City the average date of last frost happens on May 15. In the coldest months of winter you can expect an average low temperature of -30°F.

Since the USDA zone info for Miles City is not always accurate the actual date of last frost is different every year. Since half of the time in Miles City it frosts late in the year after May 15 be ready to cover your pearl onions if you have one of those late frosts.

USDA Zone Info for Miles City

Here is the info for USDA Zone 4a.

Average Date of Last Frost (spring)	May 15
Average Date of First Frost (fall)	September 15
Lowest Expected Low	-30°F
Highest Expected Low	-25°F

This means that on a really cold year, the coldest it will get is -30°F. On most years you should be prepared to experience lows near -25°F.

Plants to Grow in Miles City

You may be interested in your other planting guides for Miles City.