When to Plant Onions in Oconto, WI

One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By looking at the USDA zone info for Oconto you will be able to figure out when 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.

You can plant onions a lot earlier in the year because they are one of those plants that can tolerate quite a bit of cold weather.

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 Oconto is February. However, you really should wait until March if you don't want to take any chances.

The last month that you can plant onions and expect a good harvest is probably September. If you wait any later than that and your onions may not have a chance to fully mature. If you are starting your onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Oconto the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -20°F.

Since the USDA zone info for Oconto may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Oconto there is a last frost after April 15 so make sure that you are prepared to cover your onions if you have one of those late frosts.

USDA Zone Info for Oconto

Here is the info for USDA Zone 5a.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-20°F
Highest Expected Low-15°F

This means that on a really cold year, the coldest it will get is -20°F. On most years you should be prepared to experience lows near -15°F.

Plants to Grow in Oconto

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