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

By referring to the USDA zone info for Roseburg you will be able to figure out when it's a good idea to plant alstromeria.

Planting Calendar for Alstromeria

Frost tolerance for alstromeria:	Tolerant of some frost.
When to plant:	Up to 5 weeks before last frost.

Since alstromeria do well in moderate cold you can plant them a little bit earlier in the year than other frost tender plants.

The earliest that you can plant alstromeria in Roseburg is January. However, you really should wait until February if you don't want to take any chances.

The last month that you can plant alstromeria and expect a good harvest is probably October. You probably don't want to wait any later than that or else your alstromeria may not have a chance to really do well. You can get started a couple of weeks earlier by starting your alstromeria indoors.

Last Frost Date

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

Since the USDA zone info for Roseburg is just an average the actual date of last frost changes from year to year. Since half of the time in Roseburg you get a frost after February 15 be ready to cover your alstromeria in the event of a surprise late frost.

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.