Azalea

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Azalea

A genus (ord. Ericaceae) comprising some of the most popular of greenhouse and hardy plants, referred to the genus Rhododendron by some authorities, but generally kept distinct for garden purposes.

The so-called Indian Azaleas, mostly varieties of the species inrlica, are exceedingly beautiful greenhouse plants, and are imported largely from Belgium. Amongst hardy Azaleas there are the Ghent or American, pontica (note that this is not Rhododendron ponticum), and other varieties. Notes on culture and selections of varieties are given in the case of the principal sections. There are many species of Azaleas, but they are in the main of little horticultural value as compared with the varieties, and therefore only a summary of them is given.

Description of the Indian Azaleas.

All the greenhouse Azaleas are evergreen, and their culture is chiefly confined to varieties of garden origin. At the time when, trained specimen plants were much in vogue Azaleas were largely grown for this purpose, trained in pyramid and other shapes. For the decoration of conservatories, and for providing cut flowers, Azaleas are extremely useful. A cool greenhouse temperature suits them, and they may be grown in a cold frame or outdoors during the summer.

Propagation of Azaleas

By seeds, cuttings, and grafting.

Sowing Azaleas from Seed

Seeds should be sown in a gentle heat in February, in shallow pans. When the seedlings have made a few leaves, prick them off in other pans filled with sandy peat. The following spring they may be transferred to small pots.

To propagate from cuttings, select young, half-ripened shoots from plants that have flowered. Slip them off with a heel, trim the base, and insert half a dozen in a (3" pot three parts filled with sandy peat, with a layer of silver sand on the surface. Cover the receptacle with a bell-glass, stand it in a temperature of from 60 to 65",' and' shade from hot sunshine. When the cuttings are rooted, transfer them to small pots, using, fine peat .and sand.

Keep them in a warm temperature till roots are in action; when they may be removed to the greenhouse. Pinch out the points to cause side shoots to break, and pot on as required. Grafting is an excellent means of propagation. The early spring is the most suitable time, and indica alba and pontica are good stocks. The scions should be about 1" long, and be sidegrafted on to the stocks, and fastened with worsted. Until scion and stock are united the grafted plants should be grown in a warm propagating frame.

Soil for Azaleas

Three parts of fibrous peat, one part of loam, and one-fourth part of silver sand for Azalea soil.

Culture and Care of Azaleas

The best time for repotting established plants is directly .the flowers have faded. Prior to the operation pick off all the seed pods. The balls, when turned out of the pots, resemble a mass of fibrous roots. In the case of growing specimens, provide pots one or two sizes larger. Full-grown plants may be replaced in the same size pots.

To reduce the balls take a sharp knife and pare them round sufficiently to afford room for the new compost. Drain the pots carefully, and press the soil evenly and firmly round with a blunt stick, leaving only a slight covering of the new material over the old ball. Leave sufficient room in the pots for holding water, as plants are liable to die after potting through the old ball getting dry in the centre. Shade for a few weeks after potting, and syringe frequently.

A warm greenhouse temperature suits Azaleas after flowering. Syringe daily while new growth is being completed. Harden the growth by exposure to sunshine. About the middle of June the plants may be placed in a cold pit or stood outdoors, preferably in a western aspect. Stand the pots on a layer of coal ashes, or plunge them in Cocoanut fibre refuse.

At all times Azaleas must be carefully watered, endeavouring to keep the soil in an even .state of moisture. If the compost becomes sour through over-watering and bad drainage, the results are often fatal, and drought at the roots is equally injurious. If a plant gets very dry, the best way to ensure a thorough soaking is to sink the pot for twenty minutes in a pail of water. Towards the end of September the plants should be removed to a light, airy greenhouse for the winter. Azaleas are very useful for providing cut flowers, and free-growing varieties may be cut without injuring the plant.

Insect Pests /Enemies of Azaleas

Green fly is a source of trouble when plants are making new growth, and may be kept in check by fumigating. A far worse pest is thrips, which causes the leaves to assume a sickly appearance anil fall. Frequent syringings with clear water form the best preventive, taking care to wet the under as well as the upper side of the leaves. Thrips may be checked under glass by fumigating with a vaporising compound, and outdoor plants should be dipped in or syringed with some, approved insecticide. A simple remedy is 1 oz. of shag tobacco and 2 oz. of soft soap, boiled in 1 gallon of water, and strained and stirred before being used, but Xicotiue Soap is excellent.

Description of the Hardy Azaleas

These plants complice a number of deciduous species, but the chief interest lies in the beautiful Ghent Azaleas, most of which are seedling varieties obtained from the principal species. There are many beautiful hybrids between mollis and sinensis.

Propagation of Hardy Azaleas

By layers, seeds, cuttings, and by grafting. Layers should be notched or twisted, buried in the soil, and pegged down in March. They should not be detached from the parent till the second year's growth. Varieties are raised from seeds sown in April in boxes filled with fine peat and sand, and placed under a cold frame. The following year prick off the seedlings 2" apart in a lied of peaty soil. Cuttings are formed of yung, half ripened shoots inserted in a frame in August, and protected through the winter. To increase varieties by grafting, pontica makes a good stuck.

Soil for Hardy Azaleas

Sandy peat is excellent, but hardy Azaleas will thrive in fairly dry situations where the soil contains a good proportion of sand and leaf mould. In order to grow them where the rooting medium is stiff and retentive, it is advisable to remove a portion of the soil and make up beds of rough, samly peat and leaf mould, or good loam free from lime.' from 12" to 18" deep.

Other Cultural Points of Hardy Azaleas

When established in suitable soil, hardy Azaleas will develop into fine specimens, and no flowers are more effective in the early summer. When grown in low situations the young early shoots are sometimes destroyed by late frosts. and to obviate this it is necessary to afford some means of protection.

To facilitate the growth of young plants it is advisable to pick off the seed pods as soon as the flowers have fallen. Mollis and its varieties are much in demand for forcing, and large numbers of plants are imported from the Continent annually for this purpose. Forcing may commence in October and be continued till March.

After flowering under glass the plants should be kept indoors to finish their growth, and then be gradually hardened and planted out. They may be forced again in two or three years.