When to Plant Tree onions in Hales Corners, 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.

The best time to plant tree onions in Hales Corners should be estimated by referring to the USDA zone info.


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.

Tree onions do well in very little cold which means that you can plant them just a tiny bit 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 Hales Corners 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. Any later than that and your tree onions may not have a chance to really do well. If you are starting your tree onions indoors then you might be able to get away with starting them a couple of weeks earlier.

Last Frost Date

The average date of last frost is April 15 in Hales Corners. In the coldest months of winter you should expect an average low temperature of -15°F.

It's important to remember that USDA zone info for Hales Corners is not always accurate and the actual date of last frost will vary from year to year. Since half of the time in Hales Corners you get a frost after April 15 be ready to protect your tree onions if you have a surprise late frost.

USDA Zone Info for Hales Corners

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 Hales Corners

You may be interested in your other planting guides for Hales Corners.