Native dahlias found in the mountains of Mexico and Guatemala are the genetic source for the modern hybrid dahlias we grow today.
Dahlia is a tuberous plant, a member of the Asteraceae family. There are many species in a range of colors, sizes and forms. Flowers can be as small as 2-inches in diameter or as large as 15-inches. The tubers can go directly into the ground in the spring when the ground is warm and there is little chance of frost. Or you can start the tubers indoors in good light about a month before planting time.
Where to Plant Dahlias
Dahlias require a site with good drainage and partial to full sun. Most dahlias need to be staked to avoid falling over at maturity. The best practice is to place the stake prior to planting to avoid damaging the tuber and roots system. Plant the tuber according to the package directions with the “eye” on the tuber facing up. The eye is the point on the shoulder, or crown, of the tuber from which the plant grows.
If you are buying potted plant dahlias, simply transplant them into a prepared garden bed or decorative containers. Slugs and Japanese beetles tend to like dahlias, but they are low on the deer’s favorite list.
Source – National Garden Bureau