The USDA Zone info is a great tool for gardeners to help us determine your gardening schedule. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

The earliest that you can plant tree onions in Roseburg should be determined by referring to 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 Roseburg is February. However, you really should wait until March 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 September. You probably don't want to wait any later than that or else your tree onions may not have a chance to fully mature. If you are starting your tree onions indoors then you might be able to get away with starting them a few weeks earlier.

Last Frost Date

In Roseburg the average date of last frost happens on February 15. In the coldest months of winter you can expect an average low temperature of 20°F.

Always keep in mind that USDA zone info for Roseburg is not always accurate and the actual date of last frost can change quite a bit from year to year. Since half of the time in Roseburg it frosts late in the year after February 15 be ready to protect your tree onions in the event of one of those late frosts.

USDA Zone Info for Roseburg

Here is the info for USDA Zone 9a.

Average Date of Last Frost (spring)	February 15
Average Date of First Frost (fall)	December 15
Lowest Expected Low	20°F
Highest Expected Low	25°F

This means that on a really cold year, the coldest it will get is 20°F. On most years you should be prepared to experience lows near 25°F.

Plants to Grow in Roseburg

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