One of the best tools that you have as gardeners to help us figure out 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.

The first opportunity to plant dahlia in Roseburg can be estimated by referring to the USDA zone info.

Planting Calendar for Dahlia

Frost tolerance for dahlia:	Not tolerant of frost.
When to plant:	After the last frost has passed.

It's a bad idea to plant dahlia until after the last frost when the weather gets warmer because they are not cold tolerant.

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

Last Frost Date

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

Just be sure to remember that USDA zone info for Roseburg is an average and the actual date of last frost is different every year. Half of the time in Roseburg you get a frost after February 15 so make sure that you are prepared to protect your dahlia 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.