This section is from the book "Commercial Gardening Vol2", by John Weathers (the Editor). Also available from Amazon: Commercial Gardening, A Practical & Scientific Treatise For Market Gardeners.
The trade in these plants is practically confined to a few nurserymen, and many fine hybrids have been raised by crossing species from the Malayan and Javanese Regions With R. Mul-Ticolor From Sumatra (Fig. 298)
Rhododendrons As Grown In Nurseries.
The plants are nearly always in bloom, and vary in colour from pure white to pink, rose, salmon, crimson, scarlet, etc. They are grown in sandy peat in a warm greenhouse temperature, and like plenty of moistureduring the summer months, and also frequent syringings; to keep them free from Thrips and Mealy Bug. Propagation is by cuttings of the half-ripened shoots in a close frame.
Fig. 298. - Rhododendron - Multicolor hybrid.