Gardenia (Gardenia augusta) M ^*

        likes full sun; use blood meal as fertilizer; use fast-draining soil mix with lots of organic matter; keep crown of roots uncovered; subject to scale and spider mites; same plant as G. jasminoides ; “Radicans” is smallest-leaved variety available.   [Rubiaceae; Gentianales]

 

Gardenia – Gardenia sp.


General information: Shrub with fragrant white flowers, glossy, dark green leaves.

Family: Rubiaceae

Lighting: Partial shade to full sun.

Temperature: Zone 7 to 9.

Watering: Do not allow to dry out and remain dry. Prefers moist soil.

Feeding: Every 2-3 weeks, spring-autumn. Use a fertilizer such as Miracid, formulated for acid-loving plants, at half- strength. Do not fertilize while the plant is in bloom. The plant may also benefit from administering chelated iron 2-3 times a year.

Pruning and wiring: Wire from late spring to autumn, taking care to protect the delicate bark and branches. Do not wire while the plant is setting buds, and wire only lignified shoots. Young plants should be pruned after the shoots have developed 4-6 leaves, trimmimg back to 2-3 to establish branching. Pruning of established bonsai is best done following flowering, pruning only once and then allowing new shoots to set buds.

Propagation: Tip or midsection cuttings with wood 6 – 8 weeks old, 4 – 5 inches long with 2 or 3 sets of leaves. Cuttings may be taken any time of the year, but summer is best. May be propagated by grafting and some cultivars by seeds.

Repotting: Every 1-2 years in late winter or spring, following blooming. Well drained soil high in organic matter. Soil pH between 5.0 and 6.5.The roots are superficial and fine, so drastic root pruning is not recommended, and it is best if only 10% of the roots are removed.

Pests and diseases: Stem canker distinguished by rough cracked areas that form cankerous growths near the soil line – destroy the plant. Sooty mold, aphids, scales, mealybugs and whiteflies, cotony cushion, spider mites, nematodes.

Some species suitable for bonsai:
Gardenia radicans, a dwarf variety. Small leaved, almost creeping version of the species. 1 inch diameter flowers.
Gardenia radicans, variegated dwarf variety.
Gardenia thunbergia
Gardenia jasminoides
Gardenia ‘Aimee yashioka’

Bibliography:
University of Florida, Florida Cooperative Extension Service, Circular 1098.


Compiled by Thomas L. Zane