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

In Ypsilanti you can estimate when you can 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 do well in very little cold which means that you can plant them just a tiny bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in Ypsilanti 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 little bit earlier by starting your tree onions indoors.

Last Frost Date

In Ypsilanti the average date of last frost happens on April 15. In the coldest months of winter you can expect an average low temperature of -10°F.

Always keep in mind that the actual date of last frost may not be accurate from year to year because it is based on the USDA zone info for Ypsilanti and it is different every year. Since half of the time in Ypsilanti there is a last frost after April 15 be ready to protect your tree onions if you have a surprise late frost.

USDA Zone Info for Ypsilanti

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 Ypsilanti

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