Most commercially used method of propagation of dahalia
Answers
Answer:
Dahlia plants can be easily propagated in several ways: division of root system, cuttings, and from seed. Division of the root system and cuttings have the advantage of reliably reproducing the same flower that had been produced by the parent plant.
Propagation From Seed:
Dahlias hybridize readily; flowers of hybrids can be radically different from the flowers produced by the parent plants. So propagation from seed can result in unexpected results when it comes time for blooms. Easy hybridization has a positive aspect: a wide variety of flower forms and colors can be produced by dahlia plants, and new varieties are constantly being developed. Dahlia hybridizers work tirelessly (not to mention their plants) to develop some really spectacular flowers - great new varieties are introduced every year. The negative aspect of easy hybridization is that seeds will not relaibly produce flowers similar to the parent plant. In some cases exciting new flower varieties will result. But in most cases the flowers will not be as spectacular as the parent plant. So if you want the excitement of growing brand new varieties - plant seed, you will get interesting if not spectacular results. But if you want to know what kinds of blooms you'll be getting, it's best to propagate by division or cuttings.
Propagation by Division of Root System:
During the growing season a number of "tubers" will develop in the soil surrounding a dahlia's stems; the tubers are a part of the plant's root system. The tubers can be separated from the root system and re-planted to produce new plants the following season. The plants which emerge from the tubers will be "clones" of the parent plant - not hybrids. So they will produce flowers that are identical to the flowers of the parent plant. For the most part the plants grown at the farm come from tubers or cuttings - because there's just not a lot of room to experiment with hybrids here. (but if we had a spare acre or two there'd be some hybridizing going on)
Seattle's first Autumn frost in 2011 was in early November.; the dahlias at the farm were all going strong and producing flowers until the night of the frost. All the stems, flowers and leaves died back immediatley. That was the end of the season for flower production. But the dahlia roots are not damaged by frost. A hard freeze can cause damage if the soil is frozen to the depth of the roots, But that's a rare case for November in Seattle . So in the Seattle area it's generally OK to leave your plants in the ground through mid-November. In fact, depending on soil conditions and the severity of the weather, the plants can be left in the ground all year without a problem. But if you want to propagate your plants, November is a good time of year to remove and divide the root system.
We waited a week after the frost before digging up a number of plants at the farm. The tip of a shovel is slipped under and around the root ball and the "clump" is carefully lifted clear of the soil. Here's a photo of a plant that has been removed from the soil - the tubers are the skinny potato-like things.