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

By using the USDA zone info for Horseheads you should be able to figure out when 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 slightly earlier in the year than other frost tender plants.

The earliest that you can plant tree onions in Horseheads 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. 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 Horseheads. You can expect an average low temperature of -10°F in the coldest months of winter.

Since the USDA zone info for Horseheads may not be accurate from year to year the actual date of last frost can change quite a bit from year to year. Half of the time in Horseheads there is a last frost after April 15 so make sure that you are prepared to cover your tree onions if you have a surprise late frost.

USDA Zone Info for Horseheads

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 Horseheads

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