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.
These are sometimes troublesome, and here, as in other cases, the grower will find that "prevention is better than cure". A light weekly spraying with one of the commercial nicotine solutions will be found to prevent most of the troubles when the plants are outside; and a slight weekly nicotine fumigation will serve the same purpose inside. If the insects have got a firm hold a stronger dose at frequent intervals will be found necessary, or even an occasional dip of the whole top of the plant in a strong solution may have to be resorted to as a last resource. If even this is of no avail it will be found more profitable to burn the plant than to keep on doctoring it. Of fungoid diseases "rust" is probably the most common but not by any means the most to be feared. If the rust puts in an appearance before the plants are in bloom these should be frequently dusted over with a mixture of half each of sulphur and air-slaked lime, and all diseased leaves should as far as possible be removed and burnt. When the plants are in bloom it is not advisable to dust them over, as the lime and sulphur mixture may burn the flowers. It is then better to spray the plants with Bordeaux mixture or a solution of 1 oz. of liver of sulphur in 1 gal. of water. Care should be taken not to touch blooms and buds that show colour with these mixtures. The chief point, however, when rust appears, is to keep the atmosphere of the house dry by keeping the pipes warm, especially at night, for the spores of the rust can only germinate in drops of moisture. The "spot" is another rather common and troublesome fungoid disease. It requires practically the same treatment as the rust. Another trouble is the so-called stem rot. This is a fatal disease, attacking the base of the plants, and killing them. Some of the older varieties are principally affected by it, and as it is really a constitutional complaint, that appears in the old age of a variety, it does not seem advisable to attempt many cures, especially as none has much effect on the malady. It is best to discard and burn those varieties that suffer most, and grow others in their places that have a healthy constitution.
The growing of the Perpetual Flowering Carnation is one of the many things that cannot entirely be learned from books, but the lover of this beautiful flower who keeps an ever-watchful eye over his plants will not be long without success.
As regards varieties, it is difficult to name the best, there are now so many really good ones. Some of these give almost universal satisfaction; others appear to flourish in one district while they fail entirely in another. It is in all cases best for the grower of the Perpetual Flowering Carnation to select a collection of his favourite colours and grow them as best he can. Some, no doubt, will bring good results, and should be kept; those that fail entirely should be discarded, and some of the novelties be acquired to replace them. In this way everyone will in a few seasons get a collection most suited to the local conditions. The following will be found a good selection for growing on a large scale: -
White Perfection, White Enchantress, White Wonder.
Enchantress, Pink Delight, May Day.
Winsor, Gloriosa, R. F. Felton, Dorothy Gordon, Mrs. C. W. W. Ward.
Edith Waters, Washington.
Lady Allington, Lady Northcliffe, Rose Dore.
Britannia, Beacon, Scarlet Glow.
Malmaison Carnations have been eclipsed to a great extent by the perpetual flowering varieties, but are still grown largely and are offered in the trade in large numbers. They are cultivated in the same way as the perpetuals under glass, but flower chiefly in May and June. After this time they are usually propagated from layers which are potted up as soon as the roots are well formed, and are placed as near the glass as possible. The old " Blush" variety has given rise to many sports, including the " Pink" and "Princess of Wales". [c. E].