The USDA Zone info is a great tool for gardeners to help us figure out your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By reviewing the USDA zone info for Tiffin you will be able to estimate when it's a good idea 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.

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

The earliest that you can plant tree onions in Tiffin 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

The average date of last frost is April 15 in Tiffin. In the coldest months of winter you can expect an average low temperature of -10°F.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Tiffin and it can change quite a bit from year to year. Since half of the time in Tiffin there is a last frost after April 15 be ready to cover your tree onions in the event of a late frost.

USDA Zone Info for Tiffin

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 Tiffin

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