Preparing Dahlias After Flowering: A 4-Step Guide to Maintain Summer Arrangements and Ready for Next Year's Blossoms
Dahlias are known for their vibrant summer blooms that last until the first frost. To ensure a beautiful display of these flowers the following year, it's essential to follow some simple steps for proper care.
Cutting back
After your dahlias have finished blooming and especially following the first autumn frost (which kills the foliage), cut the plants down to about 4-6 inches above the ground. This prepares the tubers for storage and prevents disease.
Lifting and storing tubers
Carefully dig up the dahlia tubers after cutting back. Shake off excess soil and let them dry in a frost-free, shaded, and ventilated area for a few days. Remove any damaged tubers. Then store them in a cool, dry place (about 40-50°F or 4-10°C) packed in peat moss, vermiculite, or sawdust to prevent moisture loss and rot.
Replanting in spring
In late winter or early spring, before planting, divide the dahlia tuber clumps ensuring that each division has at least one "eye" or growing point. Plant the tubers in a sunny spot with well-draining soil after the danger of frost has passed. Keep the soil moist but not waterlogged as shoots emerge.
In summary:
- Cut back the plants after the first frost to 4-6 inches tall.
- Lift the tubers, dry them, and store in cool, dry conditions over winter.
- Divide and replant the tubers in spring once frost danger is passed.
Following these steps helps dahlias survive winter and bloom vigorously the following season.
Additional tips
- Some stalks can be thick, requiring a sharp blade for cutting.
- The ThermoPro TP50 Hygrometer can be used to monitor temperature and humidity for stored tubers.
- The required length for tubers to break dormancy varies, depending on storage conditions and dahlia variety.
- Dahlias will likely produce fewer blooms as summer temperatures rise or conditions become dry.
- Pre-sprouted tubers can be moved into the garden as soon as the soil has warmed in spring, provided all risk of frost has passed.
- Tubers should be packed in wood shavings, peat, or vermiculite for protection during storage.
- Dahlia tubers can be divided or stored whole through winter.
- Stored dahlia tubers can be replanted in early spring.
- Cutting back dahlias after the first frost helps to protect the dahlia variety in preparation for dormancy.
- The first frost marks the end of the dahlia growing season.
- Dahlias can also be lifted from the soil and stored indoors to protect them from cold temperatures outside the recommended hardiness zone.
- Tubers are best kept in a cool, dark place until planting in spring.
- Where hardy, tubers may be left in the ground through winter, returning to bloom again in spring.
- For an excellent display of dahlias the following year, follow automn care practices such as cutting back the plants after the first frost to 4-6 inches tall and storing the tubers in a cool, dry place over winter.
- In the spring, replant the dahlia tubers in a sunny spot with well-draining soil after the danger of frost has passed, and divide them if necessary, ensuring each division has at least one growing point.
