Home & Garden: Spectacular Dahlia manages to stand out in crowd
By Mary Jane Breitling
The fall colors have been just glorious this year especially enjoyable with the blue sky and crisp air. Even with the trees, shrubs and vines in their brilliant yellows, reds and oranges an old-fashioned flower still manages stand out in the crowd. Just as perennials and annuals began to slow down in late summer and early fall, dahlias provide great eye appeal.
Dahlia blooms range in size from 1-inch to 16-inches across and come in all colors except blue. The plants vary from tall to miniature in size and the flowers have various shapes, including anemone, pompom, semi-cactus and water lily. Dahlias originated in Mexico, growing wild in the central highlands. The Aztecs used them as medicine to treat many ills. After they were sent to Spain, dahlia fever spread across Europe. From there they were brought back to the United States. Dahlias will grow almost anywhere, but do best in the cool Northwest coastal area. Perhaps that is why they are so beautiful in our cool fall weather.
Dahlias grow from tubers that are set out once the soil warms up to 60 degrees in spring. Don’t plant them too early or they will rot. You may start them about 6 weeks before the last frost date indoors. Place the tubers as close as possible to horizontal and cover them with two to three inches of potting soil. Water them just lightly and wait until you see growth until you water again. Give them at least eight hours of light per day.
When you order dahlia tubers, you will receive a single tuber that looks like a small potato. This is actually better than a clump of several tubers. Clumps should be divided before planting, by cutting between the tubers with a knife. Make sure there is a bud or ‘eye’ on each tuber.
When it is time to plant in the ground, select a site that is in full sun or has at least eight hours of direct sun per day. Some smaller varieties may get by with six hours a day. Dig a hole about five or six inches deep and wide enough for the tuber to be horizontal with the eye facing upward. Do not water at planting time to prevent rotting. Plant potted dahlias before they get to more than 12 inches. Cut the stems back to five or six inches so that the plants will branch out later. Go easy on the fertilizer, using one that is low in Nitrogen. It should be high in Potassium and Phosphorus to encourage flowering and not so much foliage. Dahlias snap easily in the wind so you should stake tall varieties or place a tomato cage around them. It is best to do this when you plant the tuber to prevent damaging it later. Push the stake about 12 inches into the ground so it will be sturdy. The stakes should be almost as tall as the eventual plant size. Keep tying up the stem as the plant grows.
At this time of year we are more concerned about saving the dahlia tubers for next year. Since they are only hardy to zones 8 to 11 the tubers must be dug up once frost has killed the foliage. Cut the stem off to six inches before digging to make it easier. Wash off the soil and allow the tubers to dry for 24 hours. Store the tubers in a cardboard box in damp peat moss, sawdust or sand. You may attach labels to the tuber clumps with rubber bands to identify different varieties or colors. Keep the boxes in an area that stays at 40 to 50 degrees most of the time. Check them every month for shriveling and give them a spritz of water if needed. Dahlias are prolific so you should have many new plants for next spring.
Breitling is a longtime West Fargo resident and avid gardener always in search of new ideas.