One of the best tools that you have as gardeners to help us estimate your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By referring to the USDA zone info for Sylvania it's a good idea to determine when it's the best time 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.

Tree onions are barely cold tolerant which tells us that you can start planting them slightly earlier than other plants that might not handle the cold.

The earliest that you can plant tree onions in Sylvania 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. If you wait any later than that and your tree onions may not have a chance to really do well. You can get started a couple of weeks earlier by starting your tree onions indoors.

Last Frost Date

On average the last frost when the weather gets warmer is on April 15 in Sylvania. In the coldest months of winter you should expect an average low temperature of -10°F.

Since the USDA zone info for Sylvania may not be accurate from year to year the actual date of last frost is different every year. Since half of the time in Sylvania last frost occurs after April 15 be ready to protect your tree onions if you have one of those late frosts.

USDA Zone Info for Sylvania

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 Sylvania

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