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

The USDA zone info for Dewitt should be reviewed to figure out when it's possible 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.

Since tree onions do ok in moderate cold you can plant them a bit earlier in the year than more sensitive plants.

The earliest that you can plant tree onions in Dewitt 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 grow to maturity. You can get started a few weeks earlier by starting your tree onions indoors.

Last Frost Date

The average date of last frost is April 15 in Dewitt. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Dewitt is just an average the actual date of last frost is different every year. Half of the time in Dewitt you get surprised by a frost after April 15 so just be sure to be ready to cover your tree onions in the event of a surprise late frost.

USDA Zone Info for Dewitt

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 Dewitt

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