The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. 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 Belle Plaine should be used to estimate when it's the best time to plant onions.

Planting Calendar for Onions

Frost tolerance for onions:	Very tolerant of frost.
When to plant:	Up to 7 weeks before last frost.

Since onions do well in cold you can plant them quite a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant onions in Belle Plaine 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 onions and expect a good harvest is probably August. If you wait any later than that and your onions may not have a chance to really do well. You can get started a couple of weeks earlier by starting your onions indoors.

Last Frost Date

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

Keep in mind that USDA zone info for Belle Plaine is just an average and the actual date of last frost is different every year. Since half of the time in Belle Plaine last frost occurs after May 15 be ready to protect your onions if you have one of those late frosts.

USDA Zone Info for Belle Plaine

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 Plaine

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