Get more blooms from your dahlias with these tips!
Pinch and Propagate - At the start of the season, when your dahlia plant is 8-10 inches tall with at least four sets of true leaves, pinch out the top directly above a set of leaves. This technique is sometimes called topping and it encourages the plant to create an abundance of long side branches.
Thinking of composting those cuttings? Think again! With some rooting hormone and a tray of potting mix, you can root the cuttings and make more plants. Prepare a cell tray with moistened potting soil and make a deep hole in each cell with a pencil. Creating this hole ensures that the rooting hormone stays on the cutting and also keeps it from breaking. Place a small amount of rooting hormone on a disposable dish. Now you’re ready to pinch your dahlias and take cuttings at the same time.
In the early morning, cut out the central stem above four sets of leaves. Remove all but the top set of leaves from the cutting and make a fresh cut right below a node (see photos below). Dip this cutting into the rooting hormone and then stick it immediately into the moist potting soil that you’ve prepared. Snug the soil around the cutting to secure it in place.
Now treat the cuttings just as you would any other baby seedlings. Put them under grow lights or in a greenhouse and keep the soil evenly moist at all times. Don’t worry if the cuttings look sad for a few days. This is normal. Misting the cuttings daily will help keep them hydrated. One morning you will wake up and they will have perked up. After 6 weeks or so they will be ready to transplant into the garden.
Stake - Any dahlias that will grow to be more than 36 inches tall should be staked. Otherwise, the plants can fall over and the stems can crack from the weight of the flowers or a summer storm. Stake your dahlias at planting time and continue to tie them in every 12-18 inches or so throughout the growing season.
Water - Newly planted dahlia tubers should not be watered until they sprout. Once they are actively growing and approximately 24 inches tall, it’s time to begin a regular watering schedule. Soil and weather conditions vary greatly from one location to another, but your goal is to give the roots, which are approximately 8 inches below the soil surface, 1-2 inches of water per week. Deep watering 2-3 times per week is much more effective than shallow daily watering.
Fertilize - Dahlias are hungry plants and benefit from being fertilized. How much and how often to fertilize, depends on the fertility of your soil. If possible, test your soil (through your local extension service or a soil lab) before the start of the growing season.
Dahlias need a full range of plant nutrients, but generally speaking, they should get more nitrogen in their youth, and less nitrogen as they mature. Start fertilizing once the plants are 24 inches tall. Fish emulsion is an excellent early season fertilizer that can be applied once or twice a month, depending on the dilution rate and the fertility of your soil. Midseason, switch to a low-nitrogen fertilizer and continue feeding once per month. A weekly foliar feed of comfrey or compost tea is also beneficial for plant health.
Cut - Dahlias should be cut in the early morning or late evening when the flowers are well hydrated. When harvesting, make deep cuts so you get stems that are 18-24 inches long. To get stems this long, you need to sacrifice side buds. This is hard to do, but it’s the correct way to harvest and will pay off with a consistent supply of long stems.
Deadhead - Dahlias need to be deadheaded regularly so the plants can continue to send their energy into flower production. Take time to remove the entire stem right back to a main stalk. This encourages the plant to produce longer stems and also promotes good air circulation within and around the plant.
Organic pest control - Munching critters such as earwigs and Japanese beetles love to feast on dahlia blooms. Thrips can also cause damage. Luckily, there’s a safe and effective way to have perfect blooms without the use of pesticides. The solution is organza bags. Once your dahlia has formed a large bud, and before the petals have opened, enclose it in an organza bag. Use a 12×16 or 8×8 bag depending on the flower size. Pull the strings closed taking care not the crush the stem. Allow the dahlia to open inside the bag.
Start With High-Performing Varieties
Some dahlia varieties are more productive than others. If your goal is to get the maximum number of flowers, look to high volume producers such as Cornel, Blizzard, American Dawn, Maarn, Ivanetti and Cornel Bronze.
5 июл 2024
