This section is from the book "The Gardener's Monthly And Horticulturist V18", by Thomas Meehan. See also: Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long.
The scarlet Rhododendron arboreum, was first introduced into British'gardens in 1820, from Nepal. The late James Cunningham, nurseryman in Edinburgh, found it in a London nursery, bought it for a high price and took it home. The peculiar comeliness of its foliage attracted his love for the plant. When it bloomed, he was transported with joy. The leaves are of a delicate, green on the upper sides, and richly silvered on beneath. The blossom is of rich scarlet crimson of great brilliancy, and of the finest texture. The plant was a model of perfection. During its season of blooming, other species were set around it, to be impregnated by it, to originate new varieties. I had the care of it from the autumn of 1831, to the late spring of 1834. During that time the nursery was like a fair with numerous visitors to see it when in bloom (May). A dozen of other species were set under and around it to be impregnated by it; but as the flower-bells were three inches in diameter and deep, the trusses immensely large, it was feared the pollen might not flow beyond them freely, artificial impregnation was resorted to, and was fully successful.
In the morning much honey was in every bell, and was sucked out by bog-reeds to prevent the pollen from being clogged. The plant bore seeds plentifully, and increased the original species. The impregnated plants also were prolific in seed-bearing, from which numerous new and superior varieties were produced. During my time a new greenhouse was erected for their growth. It was one hundred and fifty feet long and sixteen feet wide, with an elevated bark-pit (bed). The plants were all grown in pots and plunged in the bark-pit. By the descriptions of the original species and the choice varieties in the magazines, Comely Bank Nursery became celebrated all over the United Kingdom, and also over the continent of Europe. The demand for them was far beyond the supply. I never saw such a splendid plant as is the scarlet Rhododendron arboreum when in bloom, and never knew of a plant so universally admired and sought for.
Since my time, by the works of others, (the Waterers etc, of England, and Houttes of Belgium,) the Rhododendron has been made by new superior species, the most valued and beautiful genus of ever-blooming shrubs all over Europe. Many are hardy, and grown in large masses in open pleasure grounds. Others more tender, are grown in greenhouses. Large houses are filled with them. No wealthy estate there is without its collection of Rhododendrons.