The USDA Zone info is a great tool for gardeners to help us estimate your gardening schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

A common way of estimating when it's possible to plant nierembergia is to check out the USDA zone info for Roseburg.

Planting Calendar for Nierembergia

Frost tolerance for nierembergia:	Not tolerant of frost.
When to plant:	After the last frost when the weather gets warmer.

You can not plant nierembergia until after the last frost when the weather gets warmer because they are not cold tolerant.

The earliest that you can plant nierembergia 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 nierembergia and expect a good harvest is probably September. Any later than that and your nierembergia may not have a chance to fully mature. You can get started a little bit earlier by starting your nierembergia indoors.

Last Frost Date

The average date of last frost is February 15 in Roseburg. You can expect an average low temperature of 20°F in the coldest months of winter.

Always keep in mind that the actual date of last frost is not always accurate because it is based on the USDA zone info for Roseburg and it can change quite a bit from year to year. Since half of the time in Roseburg you get a frost after February 15 be ready to protect your nierembergia if you have 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.