This section is from the book "The Gardener's Monthly And Horticulturist V23", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
In the Gardener's Monthly for April, 1881, page 110, Miss M. W. asks for information concerning the Cape Jasmine.
In reply I would say that it is a native of China, from whence it was introduced in 1754. The Cape Jasmine, Gardenia Florida fl. pl. is an evergreen shrub with elliptical leaves and large pure white deliciously scented double flowers, which are produced in the greatest abundance on well grown and healthy plants, from June to October. It requires and must have treatment adapted to its wants, and unless this peculiar treatment be given it, it should not be expected to flower, or give satisfaction as a window or greenhouse plant. It must have good drainage, a compost of two-thirds well-rotted sods from an old pasture, and one-third well-rotted manure or leaf mould well mixed, not sifted, also a light situation and a moist atmosphere. Water should be given as often as necessary and frequent sprinklings or syringings are indispensable to its doing well. During its season of growth it requires a temperature of from 65° to 75°, a moist atmosphere, and water should be abundantly given. When at rest, or during the winter season it should be given less water and kept in a cool rather dry atmosphere at an average temperature of 45°.
It is not often grown successfully in rooms owing to the dryness of the atmosphere, and when grown in rooms it is very subject to the attacks of the scale, red spider, and mealy bug, and as these insects increase with great rapidity in the hot dry air of our rooms the plant is soon injured beyond recovery. During the summer season the Cape Jasmine should be planted out in a well prepared border or plunged in a partially shaded situation where due attention should be given as to watering, etc.
The Gardenia is said to be one of the favorite plants of the Japanese who use it for hedges, and who also plant it near their houses and in the walks of their gardens. The fruit and seed of the single species are also used to dye yellow.
Whether grown in the greenhouse, window or garden an occasional washing of the leaves and stems with whale oil soap and water will prove of benefit to them.