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

You can determine when it's a good idea to plant periwinkles in Roseburg by looking at the USDA zone info.

Planting Calendar for Periwinkles

Frost tolerance for periwinkles:	Not tolerant of frost.
When to plant:	After all chance of frost has passed.

It's probably not a good idea to plant periwinkles until after the last frost because they do not do well in cold weather.

The earliest that you can plant periwinkles in Roseburg 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 periwinkles and expect a good harvest is probably September. If you wait any later than that and your periwinkles may not have a chance to really do well. Starting your periwinkles indoors is a great way to get them started a little bit earlier.

Last Frost Date

On average the last frost is on February 15 in Roseburg. It might get as low as 20°F during the coldest months of winter.

Keep in mind that USDA zone info for Roseburg is an average and the actual date of last frost changes from year to year. Since half of the time in Roseburg you get surprised by a frost after February 15 be ready to cover your periwinkles in the event of a 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.