One of the best tools that you have as gardeners to help us determine 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.

You should be able to figure out when you can plant tree onions by reviewing the USDA zone info for Arlington Heights.

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 are barely cold tolerant which means that you can start planting them slightly earlier than other frost tender plants.

The earliest that you can plant tree onions in Arlington Heights 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 fully mature. Starting your tree onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Arlington Heights. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Arlington Heights is not always accurate the actual date of last frost is different every year. Half of the time in Arlington Heights you get surprised by a frost after April 15 so always be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Arlington Heights

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 Arlington Heights

You may be interested in your other planting guides for Arlington Heights.