One of the first steps you take when you are figuring out your gardening schedule is find your 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 Belle Fourche can be looked at to determine when it's a good idea to plant bunching onions.

Planting Calendar for Bunching Onions

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

Since bunching onions are barely cold tolerant you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

The earliest that you can plant bunching onions in Belle Fourche 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 bunching onions and expect a good harvest is probably August. Any later than that and your bunching onions may not have a chance to grow to maturity. Starting your bunching onions indoors is a great way to get them started a little bit earlier.

Last Frost Date

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

Since the USDA zone info for Belle Fourche is an average the actual date of last frost can change quite a bit from year to year. Since half of the time in Belle Fourche last frost occurs after May 15 be ready to protect your bunching onions in the event of a surprise late frost.

USDA Zone Info for Belle Fourche

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 Belle Fourche

You may be interested in your other planting guides for Belle Fourche.