When to Plant Onions in River Falls, WI

The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

You can estimate when you can plant onions in River Falls by using the USDA zone info.


Planting Calendar for Onions

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

You can plant onions much earlier in the year because they do well in cold.

JanFebMarAprMayJunJulAugSepOctNovDec
Legend 
A good time to plant onions
Possibly ok, but a risky time to plant onions
Probably not a good time to plant onions

The earliest that you can plant onions in River Falls 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. Any later than that and your onions may not have a chance to really do well. Starting your onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on May 15 in River Falls. It might get as low as -25°F during the coldest months of winter.

Always keep in mind that USDA zone info for River Falls may not be accurate from year to year and the actual date of last frost can change quite a bit from year to year. Since half of the time in River Falls you get a frost after May 15 be ready to protect your onions in the event of a surprise late frost.

USDA Zone Info for River Falls

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 River Falls

You may be interested in your other planting guides for River Falls.