The ‘Koningin Wilhelmina’ peony offers a captivating display for any garden. This guide covers cultivating this specific peony cultivar, from understanding its characteristics to mastering planting and care, ensuring beautiful blooms year after year.
Discovering Peony ‘Koningin Wilhelmina’
The ‘Koningin Wilhelmina’ peony, a classic herbaceous perennial, was introduced in 1915 by Krelage and named after Dutch Queen Wilhelmina. This fragrant, double heirloom is prized for its captivating blooms and robust nature. Its flowers typically exhibit a range of hues, from pale pink to deeper fuchsia-pink, often with lighter or white petal edges.
These impressive double blooms can measure between 13 to 20 centimeters in diameter, presenting a full, bomb-type form. Known for its sweet, strong fragrance, it is a favored choice for cut flowers. It typically blooms mid-season, usually in May or June, offering a vibrant display.
As the plant matures, it forms bushy mounds of glossy, emerald-green foliage. At full maturity, ‘Koningin Wilhelmina’ can reach 70-90 cm (2 to 3 feet) high and spread 70-120 cm (3 to 4 feet) wide. This floriferous cultivar attracts butterflies.
Planting ‘Koningin Wilhelmina’ Peonies
Selecting an appropriate planting site is important for the long-term success of ‘Koningin Wilhelmina’ peonies. They thrive in full sun, requiring at least six hours of direct sunlight daily for abundant blooms, though they can tolerate some afternoon shade in warmer climates. A location sheltered from strong winds is beneficial, protecting large blooms from damage. Plant them away from trees or shrubs, as peonies do not compete well for resources.
Well-draining, fertile, humus-rich soil is important for healthy growth, with ‘Koningin Wilhelmina’ peonies performing best in slightly alkaline soil (pH 6.5-7.5). If the soil is acidic, adding lime can help raise the pH. Good air circulation around the plants is also important for preventing fungal diseases.
The ideal time for planting bare-root ‘Koningin Wilhelmina’ peonies is in the fall, allowing for thorough root system development and nutrient storage before winter. When planting bare roots, position the root with “eyes” or growth points facing upwards, no more than 1.5 to 2 inches (4-5 cm) below the soil surface. Planting too deeply is a common reason for a lack of blooms. Dig a generous 12×12 inch hole, and incorporate compost or organic matter to improve soil fertility and drainage. After placing the root, backfill gently, tamp the soil lightly, and water thoroughly to settle the soil around the roots.
Caring for ‘Koningin Wilhelmina’ Peonies
Ongoing care maintains the health and prolific blooming of ‘Koningin Wilhelmina’ peonies. Full sun promotes robust flowering, ensuring the plant’s energy production for vibrant blooms and strong foliage, though they can adapt to partial shade.
Consistent deep watering is important, especially during dry periods, to support root development and bloom production. Peonies generally require about 1 inch of water per week (approximately 2.5 to 3 gallons per plant). Avoid waterlogging, as poorly drained soil can lead to root rot. Once established, mature peonies exhibit some drought tolerance, but regular moisture contributes to healthier roots and blooms.
Fertilization should be thoughtful, as excessive nitrogen promotes leafy growth at the expense of flowers. Apply a balanced, low-nitrogen fertilizer in early spring as new shoots emerge, and again in the fall after blooming. For established plants, fertilizing every few years may be sufficient, particularly if the soil was well-amended at planting.
Due to their large, heavy blooms, ‘Koningin Wilhelmina’ peonies often benefit from staking or support to prevent stems from bending or breaking, especially after heavy rain. Deadheading spent flowers helps maintain a tidy appearance and directs the plant’s energy towards root development rather than seed production. In the fall, after the foliage has died down and turned brown, cut the stems back to the ground. Removing old foliage helps prevent the overwintering of fungal diseases.
Common Challenges and Solutions
Several issues can affect ‘Koningin Wilhelmina’ peonies, with a common concern being a lack of blooms. This can often be attributed to incorrect planting depth, as planting the root too deeply inhibits flower production. Insufficient sunlight (less than six hours daily) can also lead to fewer flowers. Young plants may need a few years to establish before blooming profusely. Over-fertilization with nitrogen can cause lush foliage but inhibit flowering.
Pests occasionally visit peonies, but ants on buds are a frequent and generally harmless sight. They are attracted to the sweet, sticky sap exuded by the buds. No treatment is typically necessary.
Regarding diseases, Botrytis blight (gray mold) is a common fungal issue, particularly in cool, wet conditions. This disease can cause young shoots to rot and buds to shrivel. Good air circulation, achieved through proper spacing, helps prevent this condition. Removing affected plant parts and ensuring fall cleanup of old foliage are important preventative measures. If powdery mildew appears (white residue on foliage), an organic fungicide or horticultural oil can be applied, ensuring ample sunlight and avoiding overhead watering.