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

By using the USDA zone info for Roanoke it's a good idea to figure out when it's possible 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.

Since dahlia are not cold tolerant you need to wait until after the last frost before you can plant them.

The earliest that you can plant dahlia in Roanoke 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. You probably don't want to wait any later than that or else your dahlia may not have a chance to really do well. You can get started a few weeks earlier by starting your dahlia indoors.

Last Frost Date

On average the last frost is on April 15 in Roanoke. You can expect an average low temperature of 5°F in the coldest months of winter.

Remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Roanoke and it is different every year. Half of the time in Roanoke last frost occurs after April 15 so be sure to be ready to cover your dahlia if you have one of those late frosts.

USDA Zone Info for Roanoke

Here is the info for USDA Zone 7b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	5°F
Highest Expected Low	10°F

This means that on a really cold year, the coldest it will get is 5°F. On most years you should be prepared to experience lows near 10°F.

Plants to Grow in Roanoke

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