This section is from the book "The Gardener V1", by William Thomson. Also available from Amazon: The New Organic Grower: A Master's Manual of Tools and Techniques for the Home and Market Gardener.
Perhaps it is beyond question that we have not a more easily managed, a more beautiful, nor a more useful Orchid than the old and well-known Dendrobium nobile. It can be had in bloom from early spring, or even from the middle of winter, to the end of June. In Dendrobium Bensonise we have quite, if not more than its equal in beauty and duration of flower. And D. Bensoniae has the recommendation of blooming from June till September, and thus so very desirably continuing a long succession of bloom from two of the most lovely and useful decorative Orchids in cultivation. It is scarcely possibly to over-estimate the beauty of D. Bensoniae. It has precisely the same habit of D. nobile, sending up from well-established plants growths from 20 to 24 inches long, which, when well ripened, are clothed from bottom to top with its beautiful clusters of flowers. Any one who can accommodate eight or twelve plants of this Dendrobe, and an equal number of D. nobile, need never be without a fine show of their lovely blossoms from January to August; for by getting them to make and ripen their growth, and resting them in succession, they are easily got to bloom in the same order, and so keep up a long succession of bloom.
D. Bensoniae was introduced from Moulmein by Colonel Benson, after whom it is named. The flowers are large - nearly 2 inches in diameter when strongly grown. They are pure white except the lip, which has a rich deep golden yellow disc, with, generally, two large brownish-purple spots near their base. It, however, varies in its markings on imported plants, some being without the spots, and are in consequence not so effective. It is a deciduous variety, and does with the same treatment as D. nobile. When making its growth it luxuriates in the East Indian house, and requires a good supply of water. The material in which it thrives is very similar to that generally used for D. nobile, viz., fibry peat, a little very turfy loam, and some sphagnum. When it has completed its growth it should have a decreased amount of water, and be inured gradually to a lower temperature to rest in. 55° is sufficient for it after it has ripened and shed its leaves, when it must be kept dry at the root, but not so absolutely dry as to cause shrivelling of the tissues. After resting for two or three months it should be introduced into a higher temperature, according to the time it is required to flower.
But little water should be given until it shows signs of throwing up young growths from the base of the previous year's ones. When in bloom it will last for five or six weeks in beauty, in a moderate temperature and comparatively dry atmosphere. The proper time to shift it is when it is done blooming and beginning to grow freely. Orchis.