When to Plant Onions in Lake Mills, 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.

In Lake Mills you can determine when you can plant onions by looking at 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.

Since onions do well in cold you can plant them a lot earlier in the year than other plants that might not handle the 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 Lake Mills 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 really do well. You can get started a little bit earlier by starting your onions indoors.

Last Frost Date

On average the last frost is on April 15 in Lake Mills. In the coldest months of winter you can expect an average low temperature of -20°F.

Keep in mind that USDA zone info for Lake Mills is not always accurate and the actual date of last frost can change quite a bit from year to year. Half of the time in Lake Mills last frost occurs after April 15 so make sure that you are ready to protect your onions if you have one of those late frosts.

USDA Zone Info for Lake Mills

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 Lake Mills

You may be interested in your other planting guides for Lake Mills.