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.

The USDA zone info for Indiana can be used to estimate when you can 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.

You can plant tree onions a bit earlier in the year because they do ok in moderate cold.

The earliest that you can plant tree onions in Indiana 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 really do well. You can get started a little bit earlier by starting your tree onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Indiana. In the coldest months of winter you can expect an average low temperature of -10°F.

Since the USDA zone info for Indiana is an average the actual date of last frost will vary from year to year. Since half of the time in Indiana you get a frost after April 15 be ready to protect your tree onions if you have a late frost.

USDA Zone Info for Indiana

Here is the info for USDA Zone 6a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-10°F
Highest Expected Low	-5°F

This means that on a really cold year, the coldest it will get is -10°F. On most years you should be prepared to experience lows near -5°F.

Plants to Grow in Indiana

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