For most of us the dahlias have been planted, and the weather has been decent to good. This year I have almost 80 plants in the ground, including several holdovers that survived our mild winter. If I were rigorous these would have been dug and dumped. But I have a soft heart.
One turned out to be a clump of Mystic Enchantment. Usually grown in a container, the bloom is a dark red with a single row of red florets (petals) along with a dark center and foliage. Mystic Enchantment, as well as the other Mystics and dahlias with multiple rows of petals are available at garden shops and even some of the "big box" stores. More and more gardeners are planting smaller-growing dahlias in pots. If you remove the spent blooms and don't forget about watering them, you will have blooms all summer.
With my son's help, we planted the tubers and plants, sprinkled a time-release fertilizer with no phosphorous (my garden is overloaded); laid horticultural cloth for weed suppression; added a soaker hose, and covered the patch with pine straw as mulch. Now that seems like a lot!
If I were growing just a few dahlias in the garden I would simply use a pine-bark mulch and water with a hose when necessary. A shot of liquid fertilizer in July would do nicely.
My mantra is that dahlias grow generally like tomatoes. They need to be loosely tied to a stake or grown in a cage so that they stay upright. If you want to maximize the number of blooms, nip the growing point of the plant when there are four to six pairs of leaves. Blooms will form on the lateral shoots that develop at the junction of the leaf and stalk
It is raining here in Virginia but if we hit a dry spell I would water once or twice a week. Beginning in July the dahlia relies on feeder roots for moisture, like virtually every other plant in the garden.
Right now, my dahlia garden resembles a parade of green stakes. But come late July, the stakes will be invisible and towers of plants and blooms will entertain the gardener until frost.
These newly planted yellow bedding dahlias
will bloom all summer.
Chemical Control NOTE: The use of chemical insecticides, fungicides and miticides are subjects of much controversy. Many experienced dahlia growers have had a tradition of relying on chemical treatments, particularly for mites. If you need specific information about controlling an infestation, visit a reputable independent garden center.