Dahlia ‘Contraste’ is a highly sought-after variety, captivating gardeners with its striking appearance. Its unique color combination and impressive bloom size make it a focal point in any garden. This dahlia is popular among enthusiasts looking to add dramatic flair to their landscapes.
Understanding Dahlia Contraste
Dahlia ‘Contraste’ is known for its distinctive characteristics. Its fully double flowers display a unique color palette, featuring deep burgundy or dark red petals adorned with pure white tips. This striking contrast in coloration gives the variety its name and visual allure.
The flower form is classified as a decorative dahlia. Individual blooms can measure up to 8 to 9 inches (20-22 cm) wide. The plant itself typically grows to a height of 36 to 44 inches (90-112 cm). This particular cultivar was originally bred in France, with a history spanning almost 60 years.
Planting Dahlia Contraste
Plant ‘Dahlia Contraste’ tubers after the last spring frost, when soil temperature ideally reaches at least 60°F (15.5°C). This typically happens in late spring, around May to early June, depending on your climate. Selecting the right site is important for optimal growth; dahlias thrive in locations that receive 6 to 8 hours of direct sunlight daily, with morning sun being particularly beneficial. Providing some protection from strong winds can also help prevent damage to the plants.
Well-draining, rich soil is ideal for ‘Dahlia Contraste’, with a preferred pH range between 6.0 and 7.5. If your soil is heavy clay, amending it with organic matter such as compost, aged manure, or peat moss will improve drainage and aeration. Loosen the soil to a depth of at least 10 to 12 inches to allow the tubers ample space to grow.
When planting, dig a hole approximately 4 to 6 inches deep and place the tuber horizontally, ensuring the “eye” or growing point faces upwards. Space individual tubers about 12 to 18 inches apart, although larger varieties may benefit from wider spacing of up to 24 inches. After planting, avoid immediate watering; instead, wait until the first green sprouts emerge from the soil.
Caring for Dahlia Contraste Through the Season
Consistent watering is important for ‘Dahlia Contraste’ once established and actively growing. Aim for deep watering two to three times per week, providing about one inch of water, adjusting frequency based on weather conditions. Dahlias in containers generally require more frequent watering due to faster soil drying. Monitoring soil moisture by checking the top 2-3 inches helps determine when watering is necessary.
Fertilization supports robust growth and abundant blooming. Apply a low-nitrogen liquid fertilizer (e.g., 5-10-10 or 5-10-15) about 30 days after planting. Repeat every three to four weeks for ground plants, and every two to three weeks for container plants. Excessive nitrogen can promote leafy growth at the expense of flowers, so a balanced approach is recommended.
Due to their height and large blooms, ‘Dahlia Contraste’ plants require staking to prevent stems from breaking. Install stakes at planting time to avoid damaging tubers later. As the plant grows, loosely tie the main stems to the stake every 12-18 inches. Regularly removing spent blooms (deadheading) encourages more flowers and extends the blooming season.
Vigilance against common pests and diseases helps maintain plant health. Aphids, spider mites, slugs, snails, and thrips are typical pests. Fungal issues like powdery mildew and gray mold, and viral diseases such as mosaic virus, may also occur. Inspecting plants regularly allows for early detection and management.
Winterizing Dahlia Contraste Tubers
In colder climates where the ground freezes, ‘Dahlia Contraste’ tubers must be lifted for winter storage. Lift tubers after the first hard frost causes foliage to die back. Cut stems to a few inches above ground. Carefully use a digging fork to lift the tuber clump, taking care not to damage the tubers.
After lifting, rinse any remaining soil from the tubers. Allow tubers to cure for several weeks in a cool, dark, well-ventilated area, preferably with indirect sunlight. This curing prepares them for dormancy and reduces rot during storage. Optimal storage conditions are cool, dark, and dry, with temperatures consistently between 40-50°F (4-10°C).
Store tubers in containers such as milk crates, plastic bins, or cardboard boxes, ensuring good air circulation. To prevent direct contact and maintain humidity, layer the tubers with materials like peat moss, coarse vermiculite, or sawdust. This storage helps preserve the tubers for replanting the following spring.