Crocosmia ‘Red King’, often called Montbretia, is a vibrant garden plant. Its fiery red-orange blooms and sword-like foliage are captivating. It adds dramatic color and vertical interest.
Understanding Crocosmia ‘Red King’
Crocosmia ‘Red King’ features funnel-shaped flowers with rich, deep red petals and yellow-orange centers, emerging on tall, arching stems to create an upright growth habit of 2 to 3 feet (approximately 60-90 cm). Its lance-shaped, mid-green leaves create a sword-like appearance. Blooming from mid-summer through mid-autumn, ‘Red King’ offers prolonged garden color. It attracts hummingbirds and butterflies, and is resistant to deer and rabbits. Originating from South Africa, this perennial is hardy in USDA Zones 5 through 9.
Planting Crocosmia ‘Red King’
Choose an appropriate site for Crocosmia ‘Red King’. It thrives in full sun for abundant flowering, but tolerates partial shade. Well-draining soil rich in organic matter is essential to prevent waterlogging. If your soil is heavy clay or overly sandy, incorporate organic materials like compost or well-rotted manure to improve drainage and nutrient availability.
The optimal time to plant Crocosmia ‘Red King’ corms is in spring, after any risk of frost has passed and the soil has begun to warm. Corms should be planted approximately 3 to 4 inches deep and spaced 4 to 6 inches apart for individual corms, or 18 to 24 inches apart when planting in larger groups to allow for future spread. Ensure the corm’s pointy end faces upwards before covering it with soil and gently pressing down. Following planting, thoroughly water the area to settle the soil around the corms.
Caring for Crocosmia ‘Red King’
Water Crocosmia ‘Red King’ consistently, especially during dry periods and establishment. Aim for about an inch of water weekly during the growing season to keep the topsoil consistently moist, ensuring good drainage to prevent corm rot. Once established, plants show good drought tolerance, though regular watering during prolonged dry spells supports better performance. It generally does not require extensive fertilization in rich soil, but a balanced granular fertilizer can be applied in spring for less fertile conditions. Container-grown plants benefit from more regular feeding to maintain vigor.
Full sun exposure yields the best blooming results. It is hardy in USDA Zones 5-9 and prefers moderate temperatures (60-80°F / 15-27°C); in colder climates (Zone 5 and below), apply a thick layer of organic mulch in autumn to protect corms from severe winter cold, or lift and store corms indoors over winter for replanting in spring. Deadheading spent blooms encourages more flowers and helps manage self-seeding. Leave foliage intact after flowering to allow photosynthesis and corm replenishment for the next season, cutting back once it yellows.
Maintenance and Troubleshooting
To maintain the vigor and flowering performance of established Crocosmia ‘Red King’ clumps, division is recommended every 3 to 5 years. This process, ideally done in spring just before new growth begins, involves digging up the clump, separating the corms, and replanting them with adequate spacing to prevent overcrowding.
Crocosmia ‘Red King’ is generally robust, but can face issues like spider mites and gladiolus thrips, managed with insecticidal soap or a strong water spray. Diseases like corm rot link to poor drainage or overwatering, causing stunted growth or yellowing leaves; well-draining soil and good air circulation prevent many problems. If blooming is poor, common culprits include too much shade, overcrowding, or insufficient nutrients; addressing these, such as relocating to a sunnier spot or dividing the clump, often resolves the issue. Crocosmia ‘Red King’ can spread vigorously as corms multiply, requiring regular division to control spread.