Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

In University Place you can estimate when you can plant tree onions by using 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 mild cold which means that you can plant them slightly earlier in the year than other plants that might not handle the cold.

The earliest that you can plant tree onions in University Place 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. If you are starting your tree onions indoors then you might be able to get away with starting them a little bit earlier.

Last Frost Date

In University Place the average date of last frost happens on March 15. In the coldest months of winter you should expect an average low temperature of 15°F.

Always keep in mind that the actual date of last frost is just an average because it is based on the USDA zone info for University Place and it will vary from year to year. Half of the time in University Place it frosts late in the year after March 15 so be sure to be ready to cover your tree onions if you have a late frost.

USDA Zone Info for University Place

Here is the info for USDA Zone 8b.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	15°F
Highest Expected Low	20°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 20°F.

Plants to Grow in University Place

You may be interested in your other planting guides for University Place.