|Gardenia subsp. var.||Rubiaceae|
They are evergreen shrubs and small trees growing to 1-15 m tall. The leaves are opposite or in whorls of three or four, 5-50 cm long and 3-25 cm broad, dark green and glossy with a leathery texture. The flowers are solitary or in small clusters, white or pale yellow, with a tubular-based corolla with 5-12 lobes ('petals') from 5-12 cm diameter. Flowering is from about mid-spring to mid-summer and many species are strongly scented.
|Standard Cyclopedia of Horticulture|
Gardenia. (after Alexander Garden, M.D., of Charleston, S. C., a correspondent of Linnaeus). Rubiaceae. Shrubs or rarely small trees, sometimes nearly or quite evergreen, some of which are planted South and one yields popular flowers for cutting.
Plants glabrous or pubescent or even tomentose: lvs. opposite or in 3's, with interpetiolar stipules: fls. large, axillary and solitary or sometimes corymbose, yellow or white; calyx-tube ovoid or obconic; corolla salver-shaped or tubular, the tube much exceeding the calyx, the limb with 5-9 spreading or recurved contorted lobes; stamens 5-9, on the corolla-throat.—Species about 60, in subtropical regions of the eastern hemisphere. See Randia for related plants.
Gardenia includes the Cape jasmine, a tender shrub 2 to 6 feet high, with thick, evergreen foliage and large double, waxy camellia-like, fragrant flowers. It blooms from May to September in the South, where it ia often used for hedges, and is hardy as far north as Virginia. In the middle of last century the Cape jasmine was considered one of the finest stove shrubs m cultivation, but with the waning popularity of camellias the doom of the Cape jasmine as a conservatory plant was sealed. The camellia has a greater range of color, and has had hundreds of varieties, while its scented rival has had barely a dozen. The flowers of the Cape jasmine have never been so perfectly regular as those of a camellia, and the plants are very subject, to insect enemies. Their bloom is successional rather than close, and large plants are therefore not so showy as camellias. They are considerably grown abroad for cut-flowers in early spring, young plants a season or two old being used for best results. The variety with variegated foliage is dwarfer and weaker-growing. The true botanical name of the Cape jasmine is G. jasminoides, a name almost never used in the trade. "Cape jasmine" itself is one of the most remarkable cases of the vitality of an erroneous popular name. The single- flowered form was introduced much later than the double, and has always been less popular. The earliest picture of a living plant with single flowers was published in 1820 in B. R. 449. Cape jasmines are also handled by importers of Japanese plants, who sometimes offer seeds also. G. lucida was probably introduced by Reasoner, and G. Rothmannia by Franceschi, who reports that it is probably riot now (1914) in cultivation. For the true jasmines (which belong to the olive family, and are often trailing plants), see Jasminum.
Culture.—The Cape jasmine of today, Gardenia veitchii, was introduced by the well-known English firm of Jas. Veitch & Son. This new variety has fulfilled the long-desired want, because it is really a winter- flowering variety, while the old species Gardenia jasminoides or G. florida could not be made to flower during the early and midwinter when actually most valuable, hence the almost total abandonment of that old variety for cut-flower purposes. This new type has become one of the most popular florist flowers, although it is one of the most difficult plants to handle. The young plants are raised from cuttings in the early winter. Care must be taken to propagate only from thoroughly healthy plants. Three- to four-eye cuttings should be put into clean, sharp sand with a minimum bottom heat of 70° and a maximum of 85°. The atmosphere should be rather close in the propagating-house until after the cuttings begin to root, then some air should be admitted. The cutting-bench must be kept shaded from the sun and frequent syringing is absolutely necessary. When fully rooted in the sand, they are potted into 2-inch pots in well-prepared soil of four parts decomposed sod loam, one part of well-rotted old cow-manure and one part sand. The soil should be well screened. Potting firmly is essential, and not too much room should be left for water. A gentle bottom heat for these young plants is highly beneficial. When the sun begins to get higher and the days lengthen, a little fresh air during the middle of the day is invigorating for the young plants, but the night temperature should never go below 65. The plants must be kept growing constantly and should be repotted as soon as they have filled their pots with roots. The months of May and June are the best time to plant gardenias into benches or solid beds. The best soil has been found to be well-rotted turf or sod, a pliable loam and well-rotted cow-manure well mixed, three parts of loam to one of manure. Should the soil be rather stiff or of a heavy texture, a portion of sand may be added. The benches should be 4 to 5 inches deep and have sufficient openings or cracks for drainage. Where very thin turf or sod can be had, the bench should be lined with this, or if not practicable, then a layer of sphagnum moss so as to cover the bottom of the bench. On top of this, a liberal sprinkling of pieces of charcoal will tend to keep the soil sweet. A small quantity of ground bone may be sprinkled over the soil after it is all spread on the benches ready for planting. Care must be taken that all balls are well softened and dissolved when planting so that there will be an amalgamation of the new soil and the soil of the ball. Firm planting and immediate watering are of the highest importance and frequent syringing after planting. Shading is not necessary, providing frequent syringing is given. Keep the soil moist but never wet. It is well to keep the house rather close for a few days, after which air can be given freely. Gardenia veitchii can stand any amount of heat, and there is no danger of burning or scorching until the foliage begins to get warm. When thermometer goes above 90° to 95° more air must be given. The plants must now make their growth and if buds appear they must be pinched out. Keep pinching out buds and small side shoots until the latter part of September when buds may be allowed to set upon the stronger shoots. A strong healthy plant can carry four to six such flowering shoots. After buds begin to set and sometimes even before, bottom shoots begin to come. These are the second growth and make for a second crop of flowers as well as for propagating the young plants for the next season. Plants are seldom kept over the second year although it can be done successfully. Young plants are decidedly the most profitable. When the plants are well set with buds, in October and November, and the roots appear on the surface, a very light mulch of cow-manure is beneficial as it will assist to develop the flowers. A night temperature of 65° to 68° is best, while during the day it may range from 70° to 90°. Good hard syringing will keep down the pests which are fond of this plant, especially the mealy-bug. The flowers should be cut before the center petals have fully expanded and the longer the stem the more valuable the flower.
Gardenia jasminoides (syn. G. grandiflora, G. florida) is cultivated as a house plant. This species can be difficult to grow because it originated in warm humid tropical areas. It demands high humidity to thrive and bright (not direct) light. It flourishes in acidic soils with good drainage and thrives on [68-74 F temperatures (20-23 C)] during the day and 60 F (15-16 C) in the evening. Potting soils developed especially for gardenias are available. G. jasminoides grows no larger than than 18 inches in height and width when grown indoors. In climates where it can be grown outdoors, it can attain a height of 6 feet. If water hits the flowers, they will turn brown. 
Pests and diseases
- Selected species
- Gardenia brighamii H.Mann - Nānū ([[Hawaii|HawaiTemplate:Okinai]])
- Gardenia buffalina (Lour.) Poir. in J.B.A.M.de Lamarck (= Genipa buffalina)
- Gardenia carinata India, Malaya.
- Gardenia cornuta (Natal Gardenia). South Africa.
- Gardenia flava (Lour.) Poir. in J.B.A.M.de Lamarck (= Genipa flava)
- Gardenia fortunei Eastern Asia.
- Gardenia gummifera India. Small tree, to 3 m high.
- Gardenia imperialis Tropical Africa. Small tree to 12 m.
- Gardenia jasminoides (Common Gardenia, Cape Jasmine or Cape Jessamine). Southern China and Japan.
- Gardenia latifolia India. Shrub or tree, 5-10 m high.
- Gardenia mannii H.St.John & Kuykend. (HawaiTemplate:Okinai)
- Gardenia remyi H.Mann (HawaiTemplate:Okinai)
- Gardenia resinifera Roth (Brilliant Gardenia, Cambi Resin Tree, or dikamali) India. Shrub or small tree, to 3 m high. (= G. lucida, Genipa resinifera)
- Gardenia resiniflua (Gummy Gardenia). South Africa.
- Gardenia rutenbergiana (Baill. ex Vatke) J.-F.Leroy (= Genipa rutenbergiana)
- Gardenia scabrella far north Queensland- used in amenities plantings in Cairns
- Gardenia spatulifolia South Africa.
- Gardenia taitensis (Tahitian Gardenia, Tiare māori). Polynesia.
- Gardenia ternifolia (Large-leaved Transvaal Gardenia). South Africa.
- Gardenia ternifolia ssp. jovis-tonantis (Welw.) Verdc. (= G. jovis-tonantis, Genipa jovis-tonantis)
- Gardenia thunbergia (White Gardenia, Forest Gardenia, or witkatjiepiering) South Africa. Shrub or small tree, 2-5 m high.
- Gardenia tubifera (Golden Gardenia). Southeastern Asia. Small tree to 15 m high.
- Gardenia turgida India. Shrub or small tree to 4 m high, with spines.
- Gardenia volkensii (Transvaal Gardenia or Savanna Gardenia). Tropical Africa.
- ↑ Reader's Digest. Success with House Plants. The Reader's Digest Association, Inc. New York/Montreal. 217
- Standard Cyclopedia of Horticulture, by L. H. Bailey, MacMillan Co., 1963