This section is from the book "The Florists' Manual", by William Scott. Also available from Amazon: The Florist's Manual.
A very large genus of shrubs or trees. Those of most commercial value are from temperate regions, South Australia and New South Wales. Some of the species, armata, for instance, make neat, compact plants for pot culture, while pubescens, one of the most graceful of all, is splendidly adapted for training on a pillar or wall of a light, cool house. A temperature of 45 degrees in winter will suit the commercial species, but their flowering can be hastened several weeks by more heat and at all times an abundance of water. They are most free flowering and the prevailing colors are lemon and yellow. In a temperature of 45 to 50 degrees most of the species flower from February to May. A good loam not too finely broken up and a fourth of leaf-mold will suit the acacias in pots. If planted out permanently in a border then it must be well drained; and some charcoal mixed with the soil will greatly help to keep it in good condition.
They are propagated from the half ripened wood in May or June, that is from the shoots made the previous spring. Place the cuttings in pans of sand or leaf-mold and sand and place the pans in a coldframe, which shade on hot days and keep close till growth begins. When rooted, pot off and grow on in a coldframe. During the follow-ing winter keep in a cool house and after danger of frost shift into larger pots and plunge outside, where they must be well supplied with water. They should be stopped as soon as they grow in the spring to induce a branching growth. Although their propagation is not difficult, it will be found by the majority of our florists more profitable to import those plants that are wanted for our spring sales, as the price of well grown, compact plants is very low and they endure the passage without the slightest injury. Any plants unsold after flowering should be cut back about half the previous summer's growth, shifted if needed, and plunged outside during summer. This applies especially to A. armata, so largely grown for Easter. Few insects of any kind attack the acacia; plenty of water at all times and syringing except when in flower is what they want.
Acacia Armata as an Easter Plant.
A. pubescens is not adapted for pot culture, but is the most graceful of all the genus, and for cutting as sprays is most valuable. It should be planted out either as a standard or against a pillar or wall. The most valuable species for pot culture for the commercial florist is armata, small globular flowers which cover the whole plant; deal-bata, strong grower with handsome yellow racemes ; Drummondii, a fine compact plant with drooping, cylindrical lemon colored flowers. There are hundreds of species, most all worthy of a place in a conservatory, but the few species mentioned above are the best for commercial use.