Gardenia

Gardenia flowers

A large genus of over 200 subtropical species, ranging from small shrubs to small trees. Usually grown as a greenhouse specimen or houseplant in the UK.

Family: Rubiaceae
Botanical Name: Gardenia
Common Names: Cape jasmine

Foliage: Evergreen, dark green, glossy leaves.

Flowers: Freshly scented, elegant, shallow dish-shaped flowers. The most popular species have white flowers but other colours include yellow and pink.

Flowering Period: Mid-summer to early autumn.

Soil: Moist but well-drained, fertile soil (clay, sand or loam). Acid or neutral pH.

Conditions: Partial shade. Grow in south facing aspect (out of direct sun) and in a sheltered position.

Habit: Bushy.

Type: Tender shrub or small tree.

Origin: China, Japan.

Hardiness: Tender in the UK - protect from frost.

Planting and Growing Gardenia

Plant in a light, free draining soil or potting compost, which is moderately acidic. Most species are best grown in a conservatory or warm greenhouse, at a constant temperature of around 16°C (60°F).

Place in partial shade, away from direct sunlight. Container grown gardenias can be moved outside in summer to a warm shaded area. Placing them where the flowers and scent can be appreciated.

Excellent as cut flowers, particularly the double forms.

Taking Care of Gardenia

Water well throughout the growing period but use less water during the winter.

To improve flowering, apply an all-purpose flowering plant food (slightly higher in phosphorus and potassium) every few weeks, or use a slow release form. Do not over fertilise.

Pruning

Deadhead regularly to extend the flowering period.

Pests and Diseases

Susceptible to attack by whitefly and mealybugs when grown under glass.

Propagating Gardenia

Propagate from seed or from hardwood cuttings taken in early winter.

Popular Varieties of Gardenia

Gardenia 'Deluxe' is a tender form with elegant creamy-white, double blooms above a mound of glossy dark green foliage. Grow as a houseplant. For sale at Thompson & Morgan.

Gardenia jasminoides (RHS Award of Garden Merit) is a medium-sized spineless shrub with fragrant white flowers. Height to 6ft (2m) if grown under good conditions. For sale at You Garden. A number of good cultivars are available, including 'Golden Crown' (PBR) a hardier form with creamy white double flowers. For sale at Crocus. 'Celestial Star' is another reasonably hardy form with pristine white, fully double blooms. For sale at Thompson & Morgan. One of the best hardy forms is 'Kleim's Hardy' which can be grown outdoors year round in mild regions. Deep glossy evergreen foliage and exquisite single white summer blooms. Height and spread to 3ft (90cm). For sale at Thompson & Morgan.

Gardenia spathulifolia is a small tree bearing creamy white flowers that yellow as they age. Height up to 17ft (5m) if conditions allow.

Gardenia thunbergia is medium sized shrub with typical shallow dish-shaped white flowers. Height up to 10ft (3m).

Gardenia 'Crown Jewels' is a beautifully fragranced, hardy outdoor variety with large pearly white, waxy double blooms above rich, glossy, evergreen leaves. For sale at Van Meuwen.