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.

In Caledonia you can determine when it's possible to plant tree onions by looking at the USDA zone info.

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 one of those plants that can tolerate a tiny bit of cold weather which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant tree onions in Caledonia 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. If you are starting your tree onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Caledonia. You should expect an average low temperature of -15°F in the coldest months of winter.

Since the USDA zone info for Caledonia is not always accurate the actual date of last frost will vary from year to year. Since half of the time in Caledonia last frost occurs after April 15 be ready to cover your tree onions in the event of one of those late frosts.

USDA Zone Info for Caledonia

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 Caledonia

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