North of the City
March/April 2008
Dahlias are back on the A-list of gardeners around the globe.
Whatever it was that dulled their lustre for post-World War II gardeners has passed — and rightly so, as there are few flowers on Earth rivalling the charms of this charismatic late-summer classic.
Renewed popularity has increased the assortment available and few flowers give more bang for the buck. These mid to late-summer bloomers offer more flamboyance per plant, and in more varied flower colours and shapes, than most other garden plants. In fact, only tulips top dahlias in number of colours.
Choose from nearly every colour under the sun (except true blue or black) and from flower types as varied in shape and size as cactus, decorative, water lily, pom pom, collarette, peony-like, dinner plate (which are truly that big) and more. In fact, official registries list thousands of named varieties.
Dahlias are tender summer bulbs (tubers, to be exact), according to the Netherlands Flower Bulb Information Center (see
www.bulb.com). They grow quickly and flower profusely, reaching their peak in the sun-dappled months of late summer and autumn.
Native to Mexico, dahlias are sensitive to frost and should not be planted outdoors until that threat has passed. To get a jump on the season, start tubers indoors in pots in early spring, then plant them outdoors when the weather has warmed garden soil to approximately 60º F (16º C) or slightly warm to the hand.
Dahlias flower in July and continue until the hard frosts of fall. If you love cut flowers, dahlias are virtual flower factories. The more you cut them, the more flowers they produce.
As tender bulbs, dahlias will not survive exposure to harsh winter weather. At summer’s end, either leave the bulbs as you would annuals, compost them, or store them in a protected spot for replanting the following summer.