One of the best tools that you have as gardeners to help us determine your gardening schedule is the USDA zone info. The zone info helps tell us things like average date of last frost and lowest expected temperature for your area.

By checking out the USDA zone info for Vienna you should be able to estimate when it's the best time to plant dahlia.

Planting Calendar for Dahlia

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

It's not a good idea to plant dahlia until after the last frost when the weather gets warmer because they do not do well in cold weather.

The earliest that you can plant dahlia in Vienna is April. However, you really should wait until May if you don't want to take any chances.

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

Last Frost Date

On average the last frost is on April 15 in Vienna. In the coldest months of winter you should expect an average low temperature of 0°F.

Since the USDA zone info for Vienna is just an average the actual date of last frost is different every year. Half of the time in Vienna there is a last frost after April 15 so just be sure to be ready to cover your dahlia in the event of a late frost.

USDA Zone Info for Vienna

Here is the info for USDA Zone 7a.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	0°F
Highest Expected Low	5°F

This means that on a really cold year, the coldest it will get is 0°F. On most years you should be prepared to experience lows near 5°F.

Plants to Grow in Vienna

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