When can I plant Tree onions in University Park, IL

One of the best tools that we have as gardeners to help us figure out our 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 our area.

In University Park you can estimate when you can plant tree onions by checking out the USDA zone info.


Planting Calendar for Tree onions

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

You can plant tree onions just a tiny bit earlier in the year because they do ok in moderate 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 University Park 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. If you wait any later than that and your tree onions may not have a chance to grow to maturity. If you are starting your tree onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In University Park the average date of last frost happens on April 15. It might get as low as 5°F during the coldest months of winter.

Keep in mind that USDA zone info for University Park is just an average and our actual date of last frost changes from year to year. Half of the time in University Park we get surprised by a frost after April 15 so just be sure to be ready to cover your tree onions if we have one of those late frosts.

USDA Zone Info for University Park

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)April 15
Average Date of First Frost (fall)October 15
Lowest Expected Low5°F
Highest Expected Low10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in University Park

You may be interested in our other planting guides for University Park.