Cerinthe glabra: complete guide

Overview

Cerinthe glabra, commonly known as smooth honeywort or Alpine wax flower, is a low-growing alpine plant from the Boraginaceae family. This species grows naturally in South and Central Europe, especially in mountain regions. The plant is favoured by gardeners and insects for its early flowering and attractive yellow and purple flowers.

This is a perfect plant for rock gardens, alpine troughs, and border fronts. Although it is a wild alpine plant, it adapts well to gardens in temperate climates and is relatively easy to grow.

Appearance and bloom

Cerinthe glabra is a compact, clump-forming plant typically reaching 15-30 cm in height. The plant has a dense, bushy growth habit with many branches. The leaves are small, lanceolate, and have a characteristic grey-green colour. This colour gives the plant a light, silvery appearance.

The flowers are the most striking feature and appear from May to August. The flowers are approximately 1-1.5 cm long and have a unique shape. The flowers are usually yellow with purple or red tips or streaks. They grow in terminal flower clusters. The flowers are also very attractive to bees and other pollinators.

Ideal location

Cerinthe glabra grows best in a warm, sunny location. Ensure the plant receives at least 6 hours of direct sunlight daily. In very warm climates, some afternoon shade can be beneficial. The plant is also very tolerant of exposure. Good air circulation is essential.

Soil

Cerinthe glabra requires excellent drainage. This is the key to success with this alpine plant. The plant grows best on poor to moderate soil. A mixture of garden soil, sharp sand, and grit works perfectly. The pH should be between 6.5 and 7.0.

Watering

Cerinthe glabra prefers dry conditions. The plant tolerates drought better than excessive moisture. Once established, the plant needs minimal water except during prolonged dry periods. During the growing period you can water moderately. Avoid wetting foliage.

Pruning

Cerinthe glabra requires minimal pruning. After flowering (August-September) you can remove spent flowers. In spring you can lightly prune the plant to encourage a more compact, bushier form. This is optional.

Maintenance calendar

January-March: Minimal maintenance. Plant is dormant. April-May: Growing season begins. Water as needed. June-July: Flowering period. Water if very dry. August-September: End of flowering. Remove spent flowers. October-November: Prepare for winter. Minimal watering. December: Winter dormancy.

Winter hardiness

Cerinthe glabra is winter hardy to approximately -15 to -20 degrees Celsius. This means the plant can overwinter outdoors in most European countries. Ensure the soil drains well in winter.

Companion plants

Sempervivum, Sedum varieties, Dianthus, Erysimum and Helichrysum share the same preference for dry, well-drained soil.

Closing

Cerinthe glabra is a beautiful, early-flowering alpine plant that enhances any alpine garden, rock garden, or border front. With good drainage and position in full sun, this plant will provide reliable flowering for years. The attraction to bees and butterflies also makes it a valuable part of an ecologically responsible garden plan. Find more information at gardenworld.app. Garden centres stock seeds and seedlings.