Upon tuber arrival, the package should be immediately opened and the tubers inspected. If you cannot immediately plant, they need to be properly stored. Store them in a cool place (do not put them in the refrigerator). If you open the top of the bag they came in you can store them in a cool place until the time of planting. Do not store within a closed bag. All of our dahlias are stored in plastic rubbermaid type containers in vermiculite with a loosely fitted lid.
Tubers can be planted into the garden after the last frost. They should be planted about 18 inches apart to give them ample room to grow. They should be placed length-wise into a six-inch hole with the shoot pointing up. Cover with tuber with soil and gently compress. We do not water them until the sprout has emerged, unless it is particularly dry. Dahlia tubers in this early stage are extremely susceptible to rot.
If you choose to start them early, you can place them in pots in the same manner as the ground. Place them under grow lights and only provide a small amount of water until they emerge. Once they are a few inches in height you can add additional water.
When the plants are 8 to 10 inches tall you can pinch out the tip of the main growth. This forces the plant to send out laterals and ultimately produces a bushier plant more blooms. This pinched portion can be turned into a cutting if you are so motivated. These plants can then be planted into the garden when you are sure there is absolutely no danger of frost.
We usually plant tubers and potted plants in deeper holes (greater than 6 inches). As the plant grows more soil can be applied around the plants. This allows for tubers to be formed along the stem above the main clump of tubers. Some of the nicest tubers with nice necks and crowns are produced this way.
Many people amend the soil at this time with bone meal or alfalfa pellets, we do not do this at Driftless. We typically add a balance fertilizer in pellet form to the base of the plants. This fits in with the results of our soil tests. It is recommended that you test your soil prior to adding any fertilizer. Free soil testing is often offered from local Universities that have a soil lab or many county extension offices.
What if you don't get the dahlia you were expecting. At Driftless Dahlia Farm we go to great lengths to make sure you get the dahlia you were expecting. We have plastic tags with thermal label that do not fade with the sun attached to the base of each plant. This label then stays with the clump during harvesting and tuber division. It also goes into the bin with the tubers during storage. The goal is to prevent mislabeling. However, there are still times when there is a mixup. If this happens, please email us with a picture of the flower and what is was supposed to be. We will send you the correct tuber in the spring or refund your money.
Good luck and happy growing. Thank you for trusting us with your dahlias, we appreciate your business.