Perpetual Flowering Carnations
The familiar carnation of the flower shops, the perpetual-flowering carnation, is so different from the border carnation that many nurseries specialize in either one or the other.
The perpetual-flowering carnation began to be developed about the beginning of this century, and it is now the most widely grown. Although the border carnation features in its ancestry, it is a hybrid involving several Dianthus species. It has a branching habit and produces a flower at the end of each branch. Theusually have petals with fringed edges, although varieties with nearly smooth edges are often grown. Fringed-edged carnations are preferred commercially as they travel better. Commercially, too, self-coloured flowers are preferred, but there are also varieties with markings similar to border carnations.
As its name implies, the perpetual-flowering carnation blooms throughout the year, and its ability to flower in the winter is one of its chief assets. It does well out-of-doors only in countries with mild winters, and in the British Isles it is grown under glass.
If perpetual-flowering carnations are to be grown on a large scale, the plants are best grown in concrete-lined beds and carefully prepared. More often, however, they are grown in pots.
These carnations will grow in any greenhouse that is large and airy and safe from frost. There should be a space of at least 2-½ ft. between the staging and the sloping glass.
Although they need considerable care in cultivation, perpetual-flowering carnations should never be coddled. Once the plants have rooted, the night temperature can be as low as -15° F. (7° C), or somewhat higher if full winter blooming is required. Although this will tend to rise considerably during the daytime, avoid high temperatures, which will cause soft growth and make the plants liable to disease.
A buoyant atmosphere is essential for these plants, and while some heat will be needed from September to April, it may also be necessary to leave the ventilators open all the year round. Only in really cold winter weather is it advisable to close ventilators in the afternoon, and leave them shut until the following morning.
Some shading will be needed if perpetual-flowering carnations are kept under glass during the summer months, and the greenhouse should be damped down regularly. Shading can be discarded in October, even if the weather is sunny, but be sure to continue giving plenty of ventilation.
The perpetual-flowering carnation is propagated by cuttings taken from a healthy, sturdy plant.
The propagating season can be said to last from November till March, but the ideal time to root cuttings is in December, so that they will be ready for potting up during the early spring, and can, if desired, be placed outside in frames during the summer. They will then flower during the following winter.
Cuttings should be taken just below a joint; they should be about 4 in. long and have four fully developed leaves. With a sharp knife, trim off the short curly leaves at the base of the cutting for about 1/2 in., so that no leaves touch the sand when the cutting is planted. Do not allow the cuttings to remain exposed to the air, but insert them immediately in the propagating sand.
Pill a propagating pan or 4-in. pot with a layer of broken crocks, covered by about 2 in. of pure silver sand, or washed and crushed river sand. Insert the cuttings into the sand I in. deep, so that they stand upright and 2 in. apart. Take care not to bury the base of any leaves. If using the same pot again and again, use fresh sand for each batch of cuttings, or they may fail to root.
Place the pots where they will receive rising heat; at this stage the temperature of the greenhouse should be somewhat higher than usual—approximately 55° F. (13° C).
The cuttings should root within 28 days, and should immediately be potted individually into 3-in. pots, using John Innes potting compost No. 1. Do not pot too deeply, and water immediately.
When these pots are filled with roots, pot up each carnation into a 6-in. pot, this time using John Innes potting compost No. 2. First give the pot a good base of broken crocks, and pile the compost over this in a mound; then place the plant’s ball of roots on this mound, with the top of the ball 1/2 in. below the top of the pot. Pack more compost round the ball of soil and, most important, press it down firmly. Carnations should be staked at this stage to encourage the stems to grow straight.
Place the pots on a bench covered with ashes, leaving about ½ in. between each pot. The plants may also, if desired, be stood out-of-doors in a cold frame from May until September in southern districts, or until about mid-August in districts farther north.
STOPPING AND DISBUDDING
When the carnations are about 10 in. tall, they should be stopped to encourage the growth of flowering shoots near the bas of the plant. Snap off about 3 in. of the growing point of the plant. Half the laterals should also be stopped when they reach a length of about 7 in., leaving the others to grow on to flower. Stopping should end by September at the latest for winter-flowering carnations.
The method of stopping described here will vary according to the time of year when the carnations are planted and when they are to be brought into flower. In general, however, a carnation will flower about five or six months after stopping has ended.
Remove all small secondary flower buds to encourage the growth of long stems and larger blooms.
WATERING AND FEEDING
Water the plants very sparingly in the winter, but give rather more water in the spring. Even in summer, water only when the plants really need it, since over-watering can have fatal results.
Syringe the plants every evening in the summer to prevent attacks by red spider.
Perpetual-flowering carnations need no feeding for the first six months. Thereafter they may be fed with special carnation fertilizer, used in accordance with the manufacturer’s directions.
SECOND AND THIRD YEARS
If the carnations are to be kept for a second year they should be transferred to 8 or 10-in. pots as early as possible, and no later than about June of the first year. Continue feeding and cultivation as before. By the end of the second season the blooms are usually considerably smaller, and although the plants may be kept for a third year, they should then be discarded.
RECOMMENDED VARIETIES :
The following varieties of perpetual-flowering carnation are not difficult to grow and give good results in pots:
Allwood’s Crimson, large, crimson, heavy cropping.
Ancient Rose, deep rose-pink shading to bronze at the edges.
Canadian Pink, short, rose-pink.
Canadian White, short and stocky, snow-white.
Doris Allwood, salmon-rose, good scent.
Fragrant Ann, pure white, scented.
Golden Rain, clear yellow, free-flowering.
Monty’s Pink, pink, scented, disease resistant.
Titian, short, crimson, a good grower.