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When to Plant Bunching Onions in Northbrook, IL

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.

A way of estimating when you can plant bunching onions is to check out the USDA zone info for Northbrook.


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 are barely cold tolerant which means that you can start planting them slightly earlier 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 Northbrook 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. If you wait any later than that and your bunching onions may not have a chance to grow to maturity. You can get started a little bit earlier by starting your bunching onions indoors.

Last Frost Date

The average date of last frost is April 15 in Northbrook. You can expect an average low temperature of -15°F in the coldest months of winter.

Just be sure to remember that the actual date of last frost is just an average because it is based on the USDA zone info for Northbrook and it can change quite a bit from year to year. Half of the time in Northbrook there is a last frost after April 15 so make sure that you are prepared to protect your bunching onions if you have a surprise late frost.

USDA Zone Info for Northbrook

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 Northbrook

You may be interested in your other planting guides for Northbrook.