One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

One way of getting a good idea when to plant tree onions is to check out the USDA zone info for The Dalles.

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 do ok in moderate cold which means that you can plant them slightly earlier than other frost tender plants.

The earliest that you can plant tree onions in The Dalles 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. You can get started a couple of weeks earlier by starting your tree onions indoors.

Last Frost Date

On average the last frost is on March 15 in The Dalles. It might get as low as 10°F during the coldest months of winter.

Keep in mind that USDA zone info for The Dalles is not always accurate and the actual date of last frost will vary from year to year. Half of the time in The Dalles last frost occurs after March 15 so make sure that you are prepared to cover your tree onions in the event of one of those late frosts.

USDA Zone Info for The Dalles

Here is the info for USDA Zone 8a.

Average Date of Last Frost (spring)	March 15
Average Date of First Frost (fall)	November 15
Lowest Expected Low	10°F
Highest Expected Low	15°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 15°F.

Plants to Grow in The Dalles

You may be interested in your other planting guides for The Dalles.