Dividing large clumps of dahlia tubers is an essential task that should be done regularly to maintain the health and quality of your dahlias. When left undivided, the clumps can become overcrowded and result in smaller plants with inferior blooms. To ensure vigorous growth and vibrant flowers, it is important to divide the tubers every few years.
1. Timing: The ideal time to divide dahlia tubers is in early spring, just as new growth begins to emerge. This allows the divided tubers to establish themselves before the peak growing season. However, if you live in a region with mild winters, you can also divide them in the fall, before the first frost.
2. Preparation: Before dividing the tubers, inspect them for any signs of disease or damage. Discard any tubers that appear rotten, shriveled, or have soft spots. It’s always better to work with healthy tubers to ensure success.
3. Digging: Carefully dig up the clump of dahlia tubers using a garden fork or shovel. Start digging a few inches away from the stems to avoid damaging them. Gently lift the clump out of the ground, being cautious not to break or snap any tubers.
4. Cleaning: Once the clump is out of the ground, gently remove the excess soil from the tubers. You can do this by lightly shaking the clump or using a soft brush. Avoid washing the tubers with water, as this can increase the risk of rotting.
5. Dividing: Look for natural divisions or “eyes” on the tubers. These are small, swollen buds that will sprout new shoots. Using a sharp, clean knife or pruners, carefully separate the tubers, ensuring that each division has at least one eye. If a tuber doesn’t have any eyes, it is unlikely to grow into a new plant and can be discarded.
6. Cutting: If the clump is particularly large, you may need to cut it into smaller sections before dividing the individual tubers. Make clean cuts between the tubers, ensuring that each section has a good balance of tubers and eyes.
7. Drying: After dividing, allow the tubers to dry for a day or two in a cool, well-ventilated area. This helps to prevent rotting and allows any cut surfaces to callus over, reducing the risk of infection.
8. Storage: Once the tubers have dried, store them in a cool, dry place until planting time. You can use paper bags or cardboard boxes filled with dry peat moss, vermiculite, or wood shavings to provide a protective and moisture-absorbing medium.
9. Planting: When the soil has warmed up and the risk of frost has passed, plant the divided tubers in their new locations. Choose a spot with well-draining soil and full sun for optimal growth. Dig a hole large enough to accommodate the tuber and its roots, ensuring that the eyes are facing upwards. Cover the tuber with soil, leaving about an inch of the neck exposed.
10. Care: Once planted, water the tubers thoroughly and continue to provide regular watering throughout the growing season. Mulching around the base of the plants can help conserve moisture and suppress weed growth. Dahlias also benefit from regular feeding with a balanced fertilizer to promote healthy growth and abundant blooms.
Dividing large clumps of dahlia tubers may initially seem like a daunting task, but with a little practice and care, it becomes a routine part of maintaining these beautiful flowers. By dividing and replanting the tubers every few years, you ensure that your dahlias continue to thrive and bring joy to your garden with their stunning blooms.
