One of the first steps you take when you are getting a good idea 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.

The USDA zone info for Bozeman can be used to determine when it's the best time to plant pearl onions.

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 more sensitive plants.

The earliest that you can plant pearl onions in Bozeman 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. You probably don't want to wait any later than that or else your pearl onions may not have a chance to fully mature. Starting your pearl onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

In Bozeman the average date of last frost happens on May 15. It might get as low as -25°F during the coldest months of winter.

Since the USDA zone info for Bozeman is just an average the actual date of last frost changes from year to year. Since half of the time in Bozeman there is a last frost after May 15 be ready to protect your pearl onions in the event of a late frost.

USDA Zone Info for Bozeman

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 Bozeman

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