Gardenia thunbergia ( Tree Gardenia ) is a flowering evergreen plant that is native to southern and eastern regions of South Africa. Tree Gardenia is a heavily scented flowering shrub or tree that produces white blooms from Spring to Autumn. They enjoy warm temperate or sub-tropical climates and are grown indoors in cooler regions. This species makes a tidy hedge, a suitable feature plant and are suitable to be planted in containers.
Suitable for Warm Temperate, Sub-Tropical and Tropical climates. Also suitable as an indoor plant in colder climates.
Also commonly known as Forest Gardenia, White Gardenia, Buffalo Ball, Blunt Thorn and Wild Gardenia.
Growth
Gardenia thunbergia is an evergreen shrub or tree that reaches heights of up to 5 metres (15 feet). Tree Gardenia enjoys warmer, humid climates but tolerates frost once established. If kept happy, Gardenias can produce an abundance of large star-shaped white blooms from Spring through to Autumn. To increase humidity, add some small pebbles to the base and direct the watering onto them.
Leaves are glossy, elliptic to oval while the flowers are fragrant, showy and up to 7-8 cm (2.5 inches) wide. The flowers long tubes are pollinated at night and only by the nocturnal hawkmoth. They bloom continuously for up to six months from Spring through to Autumn.
Tree Gardenia enjoys a slightly acidic soil which is achieved by adding vinegar or lemon juice into the watering can at a rate of 1 tablespoon to 5 litres of water. While in the kitchen, add a teaspoon of Epsom Salts to increase the magnesium intake. Yellowing leaves are a common problem for Tree Gardenias which occurs during winter stress or due to a lack of magnesium in the soil. Avoid watering the foliage to avoid fungal issues long-term.
Soil
The first of these conditions is a slightly acidic soil of a Ph Level 5.0-6.5. Lowering the natural Ph level of the soil is best done prior to transplanting. The easiest way at home is to dilute some vinegar (1 part vinegar 4 parts water) and saturate the soil prior to planting in. It may also be necessary to purchase a soil tester to check on the soil from time to time.
Watering
Finally, the watering can be a bit different for Tree Gardenia. It is better to add a little vinegar or lemon juice (just a tablespoon per 5 litres) to a watering can as it softens the water from the standard Ph Level. Not only does the softened water continue to condition the soil, it also protects the plant from chlorosis.
These are all best practices for achieving great results with Tree Gardenias. Not all of them are necessary to grow the plant successfully but they are worth knowing prior to deciding if their beautiful white flowers are worth the extra effort.
FAMILY:
Rubiaceae
CLIMATE:
Temperate (indoors or once established), Sub Tropical, Tropical
TEMPERATURE RANGE:
0°C to 30°C / 32 to 86°F
SOIL TYPE:
Humus rich, slightly acidic.
LOCATION:
Morning sun or part shade.
HEIGHT:
Up to 5 metres (15 feet)
WIDTH:
Up to 2 metres (6 feet)
pH:
5.0-6.5
GROWTH TYPE:
Evergreen
WATER REQUIREMENTS:
Medium
POLLINATION:
Hawkmoths
MATURITY:
18-24 months
GERMINATION RATES:
55-65%
GERMINATION TIME:
4-12 weeks, dependent on conditions
SEEDS PER GRAM:
Coming Soon
MEDICINAL QUALITIES:
No
WEED POTENTIAL:
No
EDIBLE:
No
SEED STORAGE & VIABILITY:
Cold Storage – 4°C (Fridge). 1-2 years
FACTS ABOUT GARDENIA THUNBERGIA (Tree Gardenia)
Members of the Johane Masowe Apostolic Church carve crosses from Tree Gardenia which they believe protects them against evil spirits.
Tree Gardenia was first introduced to Kew in England as early as 1773.
