The ‘Addison June’ dahlia features vibrant magenta-purple coloration and ball-type blooms. Each flower head has densely packed, inwardly curved petals that create a neat, spherical shape, typically measuring over 3.5 inches in diameter. This variety is highly sought after by florists and home gardeners alike because its robust, straight stems make it an exceptional cut flower. Cultivating this high-performing plant requires specific attention to its needs throughout the growing season, starting with careful site preparation.
Site Selection and Initial Planting
Selecting the right location ensures a successful season of blooms for the ‘Addison June’ dahlia. This cultivar demands a full sun environment, requiring at least six to eight hours of direct sunlight daily to produce strong stems and abundant flowers. The soil must offer excellent drainage, as tubers are highly susceptible to rot in saturated conditions, making raised beds or sloped areas ideal planting spots.
The soil structure should be rich and loamy; heavy clay can be improved by incorporating peat moss or well-aged compost, but only in moderation. Dahlias thrive best in slightly acidic to neutral soil, with a pH range between 6.5 and 7.0. After the last expected frost, plant the tuber horizontally with the developing “eye” facing upward. Due to the tuber’s large size, planting depth should be approximately four to six inches beneath the soil surface.
Seasonal Maintenance and Support
Once the sprouts emerge, the maintenance regimen shifts to hydration and nutrition. Do not water the tubers immediately after planting, as this can encourage rot before active growth begins. After the plant is established, deep watering is necessary to encourage strong root development, providing enough moisture to penetrate eight to ten inches into the soil.
Aim to water deeply two to four times per week, adjusting the frequency based on weather, increasing to daily in periods of intense heat or drought. Avoid overhead watering, which can promote fungal issues, by directing water to the base of the plant using a soaker hose or drip system. Fertilization should begin approximately 30 days after planting, using a low-nitrogen formula to promote flowers over excessive foliage.
Look for a fertilizer with an NPK ratio like 5-10-10 or 10-20-20, where the nitrogen content is significantly lower than the phosphorus and potassium. Apply this fertilizer every three to four weeks throughout the active growing season. Due to its potential height, the ‘Addison June’ dahlia requires support, which should be installed at planting time to avoid piercing the tuber later.
Staking the plant with a sturdy metal rod or using a tomato cage prevents the tall stems and heavy blooms from collapsing. To encourage a bushier plant, pinch the growing tip just above the third or fourth set of leaves when the plant reaches about 12 inches tall. Throughout the summer, deadhead spent flowers promptly by cutting the stem back to a pair of healthy leaves or a developing side bud to stimulate continuous bloom production.
Managing Common Pests and Fungal Issues
Earwigs are a primary concern, as they often chew holes in developing flower petals. They can be controlled by sprinkling food-grade diatomaceous earth around the plant base. A thin layer of Vaseline applied to the lower stem also creates a sticky barrier that prevents them from climbing up to the blooms.
Slugs and snails can be deterred with iron phosphate-based slug pellets or by creating a perimeter barrier of diatomaceous earth. Spider mites thrive in dry conditions and can be dislodged by spraying the undersides of the leaves with a strong jet of water. For a heavy infestation, a solution of insecticidal soap or neem oil can be applied in the cool evening hours to avoid leaf burn and protect beneficial pollinators.
The main fungal threat is powdery mildew, which appears as a white, dusty coating on the leaves. Prevention is achieved by stripping the lower leaves to improve airflow. If powdery mildew does appear, immediately prune and discard the affected leaves, then treat the plant with a mixture of one part milk to nine parts water, spraying thoroughly.
Winterizing and Tuber Storage
As temperatures drop, preparing the ‘Addison June’ dahlia for winter dormancy begins. Wait until the first hard frost has completely blackened the foliage. After the frost, cut the main stalks down to a handle of four to six inches above the soil line.
Allow the tubers to remain in the ground for one to two weeks after the frost; this curing period allows the “eyes,” or future growth points, to become more visible. When digging, insert a pitchfork or digging fork in a wide circle, approximately 12 inches away from the stem, to avoid piercing the delicate tubers. Gently lift the entire clump, brush off the excess soil, and allow it to dry in a cool, dark, frost-free location for 24 to 48 hours to cure the skin.
Once cured, the tubers can be stored whole or divided, but they must be labeled clearly with the cultivar name. The ideal storage environment is a dark location with a consistent temperature range of 40 to 50°F and high humidity, around 75 to 90 percent. Pack the tubers in a breathable medium such as coarse vermiculite, peat moss, or dry wood shavings, ensuring no two tubers are touching to prevent the spread of rot.