Hibiscus syriacus 'Pink Giant' - kertihibiszkusz

Hibiscus syriacus 'Red Heart', also known as “Rose of Sharon Red Heart” or “red heart hibiscus,” is a cultivar of the species Hibiscus syriacus from the Malvaceae family. This deciduous shrub, native to East Asia (China, Japan, Korea), is valued for its large white flowers with a deep red center and its long blooming period from summer to autumn. 'Red Heart' is a popular choice for gardens due to its striking floral contrast and hardiness, making it ideal for borders, hedges, or as a solitary plant.

Appearance of leaves, flowers, and fruits

• Leaves: The leaves are deciduous, dark green, ovate or three-lobed, with toothed edges, measuring 5-10 cm long. They appear late, in May, and have a palmate-veined texture. In autumn, the leaves may turn yellowish before falling but do not offer a significant color display.
• Flowers: The flowers are large, 8-10 cm in diameter, trumpet-shaped, with 5 petals. The color is a pure white with a distinctive deep crimson red spot in the center that softly radiates toward the petals, creating a “red heart” effect. They bloom from July to September, sometimes until October, each flower lasting one day but constantly replaced by new buds. The flowers have a faint fragrance and attract pollinators such as bees, butterflies, and hummingbirds.
• Fruits: It produces dehiscent capsules, green or brown, 1-2 cm in size, which persist through winter. These are not ornamental and contain seeds that can easily germinate, giving the plant a somewhat invasive character in some regions.

Growth characteristics

• Height and width: It grows as an upright shrub, reaching 2-3 meters in height and 1.5-2 meters in width within 10-20 years. It has a vase-shaped form, with long, slender branches that arch under the weight of the flowers.
• Vigor: Growth is moderate, with dense branching if pruned regularly. Flowers appear on new wood, making annual pruning beneficial.
• Type: It is a hardy deciduous shrub with a branched structure that can be shaped into various forms, including hedges or small trees.

Growing conditions

• Exposure: Prefers full sun for abundant flowering but also tolerates partial shade, with a reduction in flower number. A sunny spot sheltered from strong winds maximizes the floral display.
• Soil: Grows well in fertile, well-drained soils with consistent moisture, from slightly acidic to alkaline (pH 5.5-8). It tolerates poor soils but prefers a mix with compost or well-rotted manure. For pots, soil-based compost is recommended.
• Watering: Requires regular watering, especially in the first year, to keep the soil moist but not soaked. Once established, it tolerates moderate drought.
• Pollination: The simple flowers are very attractive to pollinators such as bees and butterflies, contributing to garden biodiversity.

Care and hardiness

• Hardiness: It is frost-hardy, withstanding temperatures down to -15°C to -20°C (zones 5-9), suitable for temperate climates, including Romania. Young leaves may be affected by late frosts, and in severe winters, mulching the base is recommended.
• Fertilizing: Apply a balanced fertilizer (e.g., 10-10-10) in spring and summer to stimulate flowering. Benefits from regular feeding during the growing season.
• Pruning: Prune in February-March to encourage flowering on new wood, leaving 2-3 buds on last year’s branches. Pruning helps maintain a compact and dense shape. Remove dead or damaged branches in spring.
• Pests and diseases: May be affected by aphids, spider mites, whiteflies, or Japanese beetles. Diseases include leaf spots, rust, or molds, especially in damp conditions. Good ventilation and avoiding wetting the leaves reduce risks.
• Propagation: Propagated by softwood cuttings taken in summer, layering, or seeds, although seeds may produce variable plants. Cuttings are the most reliable method to preserve cultivar traits.
• Toxicity: It is non-toxic to humans and animals, and the flowers are edible, used in some cultures for teas or decoration.

Uses

Hibiscus syriacus 'Red Heart' is ideal for mixed borders, hedges, privacy screens, or as a solitary plant in gardens. The white flowers with red centers add a dramatic contrast, perfect for cottage gardens, urban landscapes, or modern gardens due to its pollution tolerance. It can be grown in containers on terraces, suitable for small yards. It is excellent for attracting pollinators and creating a vibrant focal point in the garden.

Origin

Hibiscus syriacus is native to East Asia (China, India, Korea) but has been cultivated in Europe since the 16th century. The 'Red Heart' cultivar was selected for its white flowers with an intense red center, becoming one of the most popular varieties due to its visual contrast. Hibiscus syriacus is the national symbol of South Korea, known as “Mugunghwa” (eternal flower), and is mentioned in the country’s anthem.

Height including pot: approx. 30 cm