One of the first steps you take when you are figuring out your gardening schedule is find your USDA Zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The first opportunity to plant tree onions in Oswego should be figured out by checking out 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 tend to make it in very little cold which means that you can plant them a bit earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in Oswego 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 grow to maturity. Starting your tree onions indoors is a great way to get them started a few weeks earlier.

Last Frost Date

In Oswego the average date of last frost happens on April 15. It might get as low as -15°F during the coldest months of winter.

Just be sure to remember that the actual date of last frost is an average because it is based on the USDA zone info for Oswego and it is different every year. Half of the time in Oswego there is a last frost after April 15 so make sure that you are prepared to protect your tree onions in the event of a surprise late frost.

USDA Zone Info for Oswego

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 Oswego

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