The USDA Zone info is a great tool for gardeners to help us determine 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.

A common way of getting a good idea when it's the best time to plant bunching onions is to consult the USDA zone info for Glen Ellyn.

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 tells us that you can get them planted just a bit earlier than plants that are more sensitive to the cold.

The earliest that you can plant bunching onions in Glen Ellyn 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. Any later than that and your bunching onions may not have a chance to fully mature. If you are starting your bunching onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In Glen Ellyn the average date of last frost happens on April 15. In the coldest months of winter you should expect an average low temperature of -15°F.

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

USDA Zone Info for Glen Ellyn

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 Glen Ellyn

You may be interested in your other planting guides for Glen Ellyn.