by Kay Harchant, Guernsey County Master Gardener
Dahlias are a flower that is a perennial in the south, but in Ohio we cannot leave the tubers in the ground over winter. It is necessary to take the tubers up each fall to prevent their freezing. After the first killing frost in the fall carefully dig up the tubers. Wash them off. I use a garden hose outdoors and lay the tubers in the grass to dry. Cut off most of the flower stem. It is recommended to dust the tubers with a fungicide after they are fully dry.
Store your tubers in a cool, dry area in peat moss, vermiculite or sawdust. Check the tubers periodically during the winter and add water if the medium becomes dry.
In the spring the tubers can either be planted directly into the ground or in pots and then into the ground. I prefer to plant the tubers in pots first since the bed where I plant them is also my tulip bed and I like to let the tulips die back before planting over them. It is more work planting the tubers twice, but this method has worked well for me.
The tuber clumps can be divided before planting, but make sure an eye is present on each tuber clump. If you cannot see an eye, plant the tuber in moist leaf mold, peat, or airless mix. In a week or two the eyes will appear. Pot the divisions in a sterilized, soil-less mix, or porous potting soil with the crown above the potting medium.
Once the leaves begin forming and the plants are 3-4 inches tall, pinch the terminal bud just above the second pair of leaves. This will produce two main stems. Remove the buds when the flower buds are visible. This will increase the bloom size of the leader bud and improve the flower stem formation. Flower buds come in three’s. The central leader bud will produce the largest bloom. There will be a smaller flower bud on each side of the leader bud. Remove these side buds by pinching. Further down the same stem, two more buds will be found in the leaf axils and these, too, should be removed.
Dahlias are beautiful and come in an array of colors. When properly cared for they bloom constantly from July until frost. Plant and enjoy!