One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

By using the USDA zone info for Carpentersville you should be able to estimate when it's the best time to plant bunching onions.

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 plant them slightly earlier than other frost tender plants.

The earliest that you can plant bunching onions in Carpentersville 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. You probably don't want to wait any later than that or else your bunching onions may not have a chance to really do well. If you are starting your bunching onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Carpentersville. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Carpentersville may not be accurate from year to year the actual date of last frost changes from year to year. Half of the time in Carpentersville you get a frost after April 15 so always be ready to protect your bunching onions if you have one of those late frosts.

USDA Zone Info for Carpentersville

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 Carpentersville

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