Connecticut Garden Journal: How To Care For Dahlias
Our dahlias have been magnificent this year. The plants are growing large and flowering up a storm. Here are a few late season dahlia tips to keep them looking great.
For large, 5 to 6 feet tall varieties, you'll need a staking or support system. If you didn't stake them when they were young, you still can wrap chicken wire around the clump supported by stakes. This will keep the plants and flowers vertical.
To get bigger flowers, pinch off some of the smaller flower buds. Of course, if size isn't your thing, pinch the first flower to stimulate more side flower buds and make a bushier plant.
Dahlias make great cut flowers. Cut the flower stem back to a side branch. Indoors, make a horizontal cut on the stem while it sits in hot, but not boiling, water and leave it for 1 hour. This will help with water uptake and retention. Your flower should last up to a week in the vase.
Dahlias are subtropical plants and don't like the cold. After a hard frost your dahlias will turn into a blackened mess. Once killed, cut back the foliage, dig up the clump, knock off the excess soil, let dry, then store it in a box, perforated bag or bucket in a cool, dark place. Label the varieties you're storing. Cover the roots with slightly moistened peat moss or sawdust. Check periodically in winter for rotting, from too much moisture, or shriveling, from drying out. Adjust the moisture level. In spring, divide your prized dahlia tubers to create more plants for a bigger show next year.