Before planting it is a good idea to find your USDA Zone info to estimate your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

You can determine when it's the best time to plant tree onions in Seward 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.

You can plant tree onions slightly earlier in the year because they do ok in moderate cold.

The earliest that you can plant tree onions in Seward 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 fully mature. Starting your tree onions indoors is a great way to get them started a couple of weeks earlier.

Last Frost Date

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

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Seward and it changes from year to year. Half of the time in Seward it frosts late in the year after April 15 so always be ready to cover your tree onions if you have one of those late frosts.

USDA Zone Info for Seward

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 Seward

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