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When to Plant Bunching Onions in Cottage Grove, WI

Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A way of figuring out when you can plant bunching onions is to consult the USDA zone info for Cottage Grove.


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.

Bunching Onions do well in mild cold which tells us that you can plant them a bit earlier in the year than plants that are more sensitive to the cold.

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

The earliest that you can plant bunching onions in Cottage Grove 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 bunching onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else 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 couple of weeks earlier.

Last Frost Date

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

Remember that USDA zone info for Cottage Grove may not be accurate from year to year and the actual date of last frost will vary from year to year. Since half of the time in Cottage Grove you get surprised by a frost after April 15 be ready to protect your bunching onions if you have one of those late frosts.

USDA Zone Info for Cottage Grove

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 Cottage Grove

You may be interested in your other planting guides for Cottage Grove.