Iberis umbellata is a popular and easily-grown annual plant that is perhaps more versatile than you might imagine. The plants are considered one of the best plants grown for edging purposes. They are also invaluable for underplanting and for use in rock gardens and containers. Easy to grow and fast to flower, this fragrant hardy annual will quickly cover any unsightly bare spots in the garden throughout summer.
The plants spread out making mounds of foliage to around 30cm (12in) tall, and is covered with flattened 5cm (2in) dense clusters of flowers, that’s are borne on compact corymbs and bloom for many weeks.
An extremely easy to grow, hardy annual plant, Iberis umbellata is quick to grow and can be simply be sown where they are to grow in autumn or in spring. It is in bloom within two months from a spring sowing.
The plants are heat and drought tolerant, they love sunshine, and will tolerate a bit of shade. They will grow in poor soil although a moderately fertile soil is always beneficial. A little water in the driest periods of summer is all the plants require. Shear the plants after they finish blooming to keep them compact.
The plants are particularly useful for providing colourful ground cover. This beautiful white form has glossy green leaves and the familiar clusters of snow white, fragrant flowers which are attractive to bees, butterflies and other pollinating insects.
Sowing: Sow in autumn or in spring.
Seeds of Iberis umbellata, the hardy annual candytuft can be sown in autumn or in spring.
They can be sown early indoors or directly where they are to flower. Sown in succession they will give continuity of blooms. The plants prefer a position in full sun but will tolerate some shade. ideally receiving sun for half the day or more. Germination will normally occur within 7 to 21 days at temperatures around 20 to 22°C (68 to 72°F).
They germinate best at warmer temperatures of around 20 to 30°C (68 to 86°F), most will germinate within ten days. At lower temperatures they germinate erratically over a period of 10 to 30 days.
For earlier blooms, the seeds may be started indoors in spring, 6 to 8 weeks before planting outside. Sow into pots or trays containing a good quality seed starter compost. Lightly cover seed with soil, and make sure the seedlings have plenty of light and protection from cold.
The plants have a long taproot so if you sow indoors do not leave pricking out and transplanting for too long otherwise the plant will suffer and may never recover. The taproot can easily be damaged so care must be taken. Harden off and transplant to the garden after the last frost and temperatures begin to warm. Plant into moist, well-drained soil, 20 to 30cm (8 to 12in) apart
Direct sow where the plants are to flower from March to May for flowering from June to September. The seeds can be sown in succession from March through to May for continued flowering throughout the summer.
If sowing directly where they are to flower, prepare the ground well and rake to a fine tilth. If sowing more than one annual in the same bed, mark the sowing areas with a ring of sand and label. Ensure that any weeds are removed, especially during the early stages of growth. In cooler times of year, they will grow faster under a cloche or plastic tunnel.
Sow thinly 1 to 2cm (½ to 1in) deep in rows approximately 20cm (8in) apart.
Water ground regularly, especially in dry periods. The seedlings will appear in rows and can be easily told from nearby weed seedlings. When large enough to handle and they have reached 5cm (3in) tall, thin the seedlings out so they are finally 20 to 30cm (8 to 12in) apart by early summer.
Water regularly especially in very hot weather. In poor soils, the plants will benefit from a light application of a water soluble balanced fertiliser.
Shear the plants after they finish blooming to keep them compact. At the end of the season leave a few plants to die down and self seed, others can be pulled up and composted.
Iberis flowers, although shorter than most flowers that are grown for cutting are perfect for use as in small romantic bouquets. In a small jug or vase, the fragrant flowers will last for over week. Cut the nicest blooms early in the day and place immediately in a vase of water for best results.
Cottage/Informal Gardens, Edging plants, Underplanting. Container and basket planting.
Iberis umbellata is native to the Mediterranean region, but is also present in much of Europe, especially along the coasts, from Spain to Greece and also in northern America. It grows in dry rocky hillsides, in bushy areas and in clearings, preferably on calcareous soils, at an altitude of 0 to 1,300 metres (0 to 4,265ft) above sea level. During the 16th century, it was brought from Crete to England.
A member of the mustard family, thus the four petals per flower, this Colonial favourite was used for centuries as a seasoning and always included in the herb garden as a treatment for rheumatism.
The genus name Iberis derives from ‘Iberia’, the ancient name of Spain.
The species epithet comes from the Latin umbel, meaning ‘like an umbrella’ and refers to the shape of the inflorescence.
Iberis umbellata is also referred to as the Annual or Globe Candytuft. The name Candytuft conjures up images of sweet confections, but it is actually named for the Mediterranean area of Candia, the former name of Iraklion on the Island of Crete.
It is often referred to as the annual form to differentiate it from perennial species. Iberis gibraltarica and Iberis sempervirens are perennial forms that can also be grown from seed.
Synonym: Iberis commutata.
- Additional Information
Packet Size 2 grams Average Seed Count 800 seeds Family Brassicaceae Genus Iberis Species umbellata Cultivar White Synonym Iberis commutata Common Name Annual or Globe Candytuft Hardiness Hardy Annual Flowers White globe-shaped blooms Natural Flower Time May to July Height 30 to 60cm (12 to 24in) Position Full sun for best flowering Soil Any soil. Germination 7 to 10 days at 22*C (70*F)