Bringing Chrysanthemums into Flower
THE aim of this phase of culture is not so much to put more into the plant, but rather to allow what is already in to come to fruition without hindrance. As a result of careful treatment from the cutting stage onwards, the plant has enough strength to produce its crop without further feeding. Many growers do continue a modified feeding programme after housing, but there are many dangers and the slightest mistake can ruin a whole collection. A safer plan, giving first-class results, is to give the final top-dressing just prior to housing and to restrict the plants to. Experience will show that correct atmospheric conditions are of far greater importance than feeding, and the beginner is advised to study the following points very closely. A well-grown plant may fail to fulfil its promise if the final stage is mishandled.
is Most Important
At all timesis of paramount importance. Moist, stagnant air is responsible for the loss of more blooms than any other cause, and every effort should be made to produce a dry, moving atmosphere without draught. In the first few weeks after housing this can be effected by merely opening ventilators, but as outside conditions worsen and blooms grow larger a little heat is invaluable. Note that it is a little heat, for forcing temperatures never suit the chrysanthemum. The heat is required not for raising the temperature but to create a moving current of air, and it should always be accompanied by open ventilators. This is of supreme importance on muggy days often experienced in October and November, when everything is dripping with moisture and the thermometer stands comparatively high. These conditions if established indoors will spell disaster, and the fire should be lighted and the ventilators used to get the air moving. Amateur electricians may care to rig electric-fans for the same purpose. Ventilators should be closed only in severe fog or frost, and must be opened as soon as possible. While high temperatures are inadvisable it is equally dangerous to allow wide fluctuations, such as those between near-freezing at night and 60° F. under sunlight during the afternoon. Aim at a perfectly steady warmth ranging no more than 5° either side of 50° F. Cold periods after warmth cause condensation on the florets, which soon spot and damp-off. For the same reason, be careful with the can, doing all the watering as far as possible on the mornings of bright days so that all moisture has dispersed before ventilation has to be reduced a little at night.
Shading can be Helpful
Shading of buds is often helpful. The sun still has great power throughout October and spotting of the florets at this early stage is often due to its strength, particularly when ventilators are not opened out before mid-morning. Condensation on the petals will concentrate the sun’s rays and produce burning. Muslin or similar material tacked to the inside of the roof is very convenient, but whatever shading is supplied must be very light and ought to be removed altogether after, say, mid-October.
Fumigation should be carried out at 10-day intervals. Smokes containing DDT and BHC are very effective, persistent in effect and quite safe, and though all pests should be cleared before the flowers are open, last-minute fumigations at the correct strength have been carried out without damage to the blooms.
Take Precautions against Foliage Troubles
However thorough the pre-housing spray, there is always the possibility of foliage troubles in the more confined conditions of the house. At least once a week remove all faded leaves and burn them immediately. As flowers go over, rearrange the plants to give more room, for with adequate light and air, the foliage will remain healthy to the last. Shouldbe seen, dust with green sulphur, especially on the undersides of the leaves.
Examine Blooms Carefully
Occasional florets will damp off and must be carefully removed before the trouble spreads. Tweezers are very useful, though fingers can be trained to the job almost as well. Don’t hesitate to remove coarse or misplaced florets which threaten to spoil the symmetry of the bloom. Should you feel nervous about it, practise on less-important flowers first. Large Exhibition blooms often give coarse florets at first, a typical example being Shirley Primrose which has been known to give a whole ring of small flower buds! It would obviously be a mistake to leave such growths, as they can seriously impede the opening of the remaining florets. Singles can also come a little untidy and florets that appear on the central disk should be removed as soon as possible, and if it is done carefully the gap left will close up. Modern Incurves need very little dressing, but a floret may occasionally turn the wrong way. If possible guide it aright with a soft brush, but if all attempts fail then get it out. Occasionally a reflexed type will open slightly incurving, and if the job is carefully done the florets may be stroked into their correct form while still on the plant, thus saving time when preparing for a show.
Get Rid of Diseased Stock
While plants are in flower go over them to be rid of any that show signs of degeneration or disease. Be ruthless and select only the very best as parents for the new generation, marking them very carefully for they all look the same when cut down. Any showing symptoms of chrysanthemum mosaic should be destroyed by burning without delay, for a few aphis unnoticed may transfer the trouble to healthy stock. Some cannot bear to throw anything away however suspect its health or quality, but such false economy usually ends in a collection being simply riddled with disease. The chrysanthemum has been developed by intensive breeding over many years and its blood is very unstable. New varieties sometimes fall right away in two or three, though others, like Majestic, are nearing the half-century mark. This instability of blood will need watching even in a small collection. Deterioration may take place in individual plants, and they must be excluded to safeguard the quality of future stock. Similarly, apart from the chance of a sport, there can easily be an improvement of colour or quality in individual plants, and by selecting these as parents the stock can be built up on the basis of improved quality. It is not easy to be critical of one’s own blooms, but the art must be learnt, for the grower who is not easy to please is not easy to beat either.