Gardenia
Gardenia jasminoides
An evergreen Asian shrub with glossy dark-green leaves and intensely fragrant pure-white double flowers that age to cream as they open. The scent is the main attraction: a single bloom can perfume an entire room. Notoriously fussy as a houseplant and often blamed unjustly for being difficult. Most failures trace to one of three causes: alkaline tap water, dry indoor air, or temperature swings. Get those right and gardenia rewards you with months of blooms. In Alberta, supplemental humidity from a humidifier or a pebble tray is usually essential through the winter, since indoor air commonly drops to 20 percent humidity or lower.
Quick Facts
Distribution
Indoor (native to East Asia, primarily southern China and Japan)
Light
Bright indirect light to several hours of morning direct sun. Grow lights help in Alberta winters
Bloom Time
Late spring through fall, with a winter rest period
Soil
Acidic, rich, well-draining mix. Standard houseplant mix amended with peat or pine bark works well. Target pH 5.0 to 6.0
Water
When the top 2 cm of soil is dry. Use rainwater, distilled water, or filtered water if your tap is alkaline. Mist daily or use a humidifier; aim for 50 percent humidity or higher
Growing & Cultivation
Propagation
Semi-hardwood stem cuttings 10 to 15 cm long, taken in late spring. Strip the lower leaves, dip the cut end in rooting hormone, plant in moist seed-starting mix, cover with a clear plastic bag, and keep at 20 to 24 C with bottom heat. Roots in 4 to 8 weeks
Pruning / Splitting
Light pruning right after the last bloom to maintain shape. Avoid pruning in late summer or fall: next season's flower buds are setting then and aggressive cuts will sacrifice the next display
