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When to Plant Tree onions in South Milwaukee, WI

The USDA Zone info is a great tool for gardeners to help us figure out 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 South Milwaukee can be read to determine when you can plant tree onions.


Planting Calendar for Tree onions

Frost tolerance for tree onions: Tolerant of a very small amount of frost.
When to plant: Up to 3 weeks before last frost.

Since tree onions are one of those plants that can tolerate a tiny bit of cold weather you can plant them slightly earlier in the year than other plants that might not handle the cold.

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

The earliest that you can plant tree onions in South Milwaukee 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 tree onions and expect a good harvest is probably August. You probably don't want to wait any later than that or else your tree onions may not have a chance to grow to maturity. You can get started a few weeks earlier by starting your tree onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in South Milwaukee. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that USDA zone info for South Milwaukee is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in South Milwaukee it frosts late in the year after April 15 be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for South Milwaukee

Here is the info for USDA Zone 5b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low-15°F
Highest Expected Low-10°F

This means that on a really cold year, the coldest it will get is -15°F. On most years you should be prepared to experience lows near -10°F.

Plants to Grow in South Milwaukee

You may be interested in your other planting guides for South Milwaukee.