Before planting it is a good idea to find your USDA Zone info to figure out your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

The USDA zone info for Olympia Fields should be reffered to in order to figure out when it's the best time to plant tree onions.

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 Olympia Fields 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. You probably don't want to wait any later than that or else 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 few weeks earlier.

Last Frost Date

On average the last frost is on April 15 in Olympia Fields. It might get as low as -15°F during the coldest months of winter.

Since the USDA zone info for Olympia Fields may not be accurate from year to year the actual date of last frost changes from year to year. Since half of the time in Olympia Fields you get surprised by a frost after April 15 be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Olympia Fields

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 Olympia Fields

You may be interested in your other planting guides for Olympia Fields.