This section is from the book "The Standard Cyclopedia Of Horticulture Vol2", by L. H. Bailey. See also: Western Garden Book: More than 8,000 Plants - The Right Plants for Your Climate - Tips from Western Garden Experts.
The Malmaison strain, which was the leading carnation in England before the advent of the Perpetual-flowering strain, has been found of little value in this country. On account of its large size it was used to some extent for breeding purposes, but with unsatisfactory results.
The border carnation is a more condensed and bushy plant than the long-stemmed few-flowered plant seen in the American greenhouses, although there are different families or groups of them as there are of phlox or snapdragons. Some forms are dwarf and some tall-growing.
American methods of culture for indoor bloom.
The modern method of propagating the carnation for commercial growing is by means of cuttings which are taken from either the blooming stock or from plants that are grown for cuttings alone. The old method of layering (Fig. 809) would prove too slow in increasing stock for present-day needs. Millions of cuttings are rooted each season for planting the houses for blooming purposes. So much depends on the quality of the cuttings in keeping up the vitality in the stock that expert growers have learned to discriminate in their selection. The best cuttings, if taken from the blooming stock, are those from near the middle of the flower-stems (Fig. 810). These will not only show greater vitality than those taken higher up or lower, but they will prove more floriferous The tip cuttings are likely to give a flower-bud immediately and, if this is pinched out, develop into a weak plant. Those taken from the base develop a large spreading growth known as "grassy." The cuttings are severed by an outward pull and are afterward trimmed of all surplus foliage before being inserted in the propagating sand. Have a sharp knife with which to trim and a pail of fresh water into which to throw the cuttings as they are trimmed.
Make a smooth cut at the base, near the joint, so that the lower pair of leaves will peel off readily, leaving a half-inch of clear stem to go into the sand. Shorten those leaves which turn outward, leaving those which stand fairly upright. The removal of part of the foliage is to avoid crowding in the bench and also to prevent flagging while the cutting is giving off more moisture through its leaves than it is taking up through the stem. The cuttings are inserted in the sand about 3/4inch deep in rows across the bench, placing the cuttings about 3/4inch apart in the row and the rows about 2 1/2 inches apart, according to the size of the cuttings. Use a putty knife for making the cut in the sand. The sand is kept constantly moist and the cuttings are protected from both the sun and drafts by means of muslin curtains. Frequent spraying should be avoided, though it must be resorted to at times to prevent flagging on warm windy days. The most favorable conditions for propagating are usually secured during the months of December, January, February and early March. During that period, ventilation is limited and a fairly even bottom-heat is easily maintained.
Keep a bottom temperature of about 60°, while the overhead temperature should be about 52°. Any bench that can be protected from sun and drafts will prove satisfactory.
Fig. 807. Carnation, Little Gem. A striped flower.
The bottom of the bench may be of wood or tile, the latter being preferred on account of more perfect drainage and a greater retention of warmth. The sand should be 3 inches deep after being packed down by means of a tool made from a 2-inch plank about 6 inches wide and
12 inches long with an inverted V-shaped handle. In about four weeks the cuttings should be ready for potting (Fig. 811). Those that come out of the sand February 15 or earlier should be potted first into 2-inch pots and later on shifted into larger pots as needed. Those potted later may be placed directly into 2 1/2-inch pots and left until planted out, the object being to keep the young plants growing steadily until they are planted in the field. Stunted, pot-bound plants will be slow in breaking and are likely to develop stem-rot in the field. Use a moderately light soil and only fairly rich.
Fig. 808. Flower-garden or outdoor carnation, showing the condensed bushy habit and short flower-stems.
When the young plants begin to run up to flower, they should be topped back to about four joints above the pot (Fig. 812). A low-branched plant will stand up better and will give less trouble in supporting later on. A second topping may be necessary before planting-out time, on early-propagated stock. A slight harden-ing-off of the young plants before planting out is beneficial, though not essential. This is usually done by placing the plants in coldframes about two weeks prior to planting them in the field. Late April or early May is the time for planting in the field, according to latitude and climate. A rich loam, inclined to sandiness, produces the finest plants in the shortest time. In a heavy soil the growth will be heavier, but slower and less branching. Set the plants about 8 inches apart in the rows, and if hand-power is to be employed in cultivating, space the rows about 16 inches apart. Space farther if horse-power is to be used.
When a large business is done in young plants or rooted cuttings, a part of the stock is grown especially for cuttings alone. These plants are benched the same as those for blooming, but are not allowed to bloom. As the shoots begin to run up to flower, they are broken off a few joints higher up than is done when topping in the field. The young shoots which result from these breaks are taken off for cuttings, the very finest cuttings being secured in this way. These are trimmed and handled the same as those taken from the flower-stems.
Fig. 809. Layer of carnation. The parent stem was severed at s. This method is now employed only in special cases.