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.

In Roanoke you can determine when to plant dahlias by reviewing the USDA zone info.

Planting Calendar for Dahlias

Frost tolerance for dahlias:	Not tolerant of frost.
When to plant:	After the last frost.

You should not plant dahlias until after all chance of frost has passed because they require warm weather.

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

Last Frost Date

The average date of last frost is April 15 in Roanoke. It might get as low as 5°F during the coldest months of winter.

Always keep in mind that the actual date of last frost is an average because it is based on the USDA zone info for Roanoke and it is different every year. Half of the time in Roanoke there is a last frost after April 15 so be sure to be ready to cover your dahlias in the event of 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.