PITFALLS OF BULB FORCING

Otago Daily Times, Issue 21988, 24 June 1933, Page 7

PITFALLS OF BULB FORCING

It is a simple enough matter to grow bulbs in pots or bowls, and flower them under glass or in a sunny window a few weeks ahead of their natural blooming time out of doors. But it is by no means so easy to obtain ’good flowers several months in advance, for various pitfalls await - the unwary when an attempt ia made to hustle growth at a rapid pace. , The one into which the beginner most commonly falls is that of being in too great a hurry to introduce bulbs into a warm atmosphere. Closely allied with this is the equally fatal error of failing to pot the bulbs sufficiently early in the season. It is absolutely essential that the bulbs should remain for at least eight, weeks—--10 ia better —buried under a deep layer of ashes or peat moss litter in a cool place out-of-doora. ' Only by this means can they be induced to make sufficient roots to sustain the rapid growth which will take place when they are brought into the warm atmosphere of the forcing house. Usually it is not necessary to water the bulbs so long as they are in the plunging bed, as the natural rainfall proves sufficient. But they musT not be allowed to puffer from drought, and should a long dry spell be experienced in the autumn must be given a thorough soaking. Before introducing a batch to the greenhouse lift out one of the pots or boxes and examine the base carefully. _ If the bulbs have rooted freely, some white rootlets should be detected pushing through the drainage holes in the bottom of the receptacle. If none can be seen leave the whole batch a week longer, and examine again. On no account commence forcing until it is certain that roots have penetrated the body of soil in the pots or boxes. For the first few days after introducing bulbs to the house they should be shaded from strong sunlight. The young growth will be blanched from the plungijjg bed, ana must be allowed to gather its normal colour gradually. But of far greater importance than this is the fact that too high a temperature must not be used at the outset. Plants, like human beings, are susceptible to sudden changes, and the shock of a rise in temperature of 30 degrees or more is likely to cause them considerable distress.

It is a great advantage if two houses can be employed for forcing, or if one house can be divided into two sections which can be heated and ventilated independently. Then the bulbs can be brought from the plunging bed into a-tempera-ture of about 50 to 55 degrees, rising, after the first fortnight, to CO degrees. Ventilation in this house should be free, though cold draughts must be avoided. In a span-roofed structure the ventilators can be opened on the lee side, but in a lean-to ventilation is more difficult. Never use the side ventilators, as these almost always cause chilly air currents around the pots. Rely on those in the roof, and only open them a fraction if the wind is cold and is blowing upon them. When the flower buds are well developed, the bulbs can with safety be introduced to the forcing house prdper, in which a minimum temperature of 65'deg may be maintained, rising to 70deg for the last few days, when the buds are showing colour, if it is desired to hurry them along a little. Another common cause of failure is dryness at the root. In the high temperature of the forcing house transpiration is very rapid, and it is necessary to examine the pots or boxes daily, preferably in the morning when the temperature is rising. Never use water direct from a tap or an outside cistern. If possible, a tank should be . placed in the house itself, and kept filled with rain water, so that the latter may be warmed to the same temperature as that in which the bulbs are growing. But failing this, some provision must be made for taking the chill off the water. If nothing better can be arranged, a sufficient supply for the morning watering should be stood in the house overnight in buckets or cans. As soon as the soil begins to show signs of dryness apply sufficient water to soak it right through. On no account give incessant driblets from a can fitted with a line spray. These make the soil appear moist on the surface, but leave it quite dry underneath, and this pernicious habit is the cause of much disappointment. Greenfly is a common cause of trouble, especially with tulips, and a keen watch must be kept for this pest. It is surprising what damage even a few will cause, for they attack the tender growing points of the nlants. and bring about all manner of malformations. It there is the least sign of an attack the house should be fumigated with nicotine. A few pots can be dealt with by sponging, using for this purpose soapy water containing a little nicotine insecticide at the strength recommended by the manufacturers. It is essential to use suitable varieties of bulbs of very early blooms are desired. Those which naturally flower late, such as the Darwin and Cottage tulips, should be left for the expert if tire object in view is to have blooms by Christmas. For this purpose Roman hyacinths, Polyanthus narcissi, and Due van Thol tulips are most suitable. The early trumpet daffodil, Princeps, also stands forcing well. Miniature hyacinths, Cynthella hyacinths, and prepared hyacinths are available for pot work and for early forcing, and such should be grown for the purpose, potting them in August as soon as procurable. For decorative purposes forced Due van Thol tulips are lifted from boxes and potted wifb a seedling fern into four and a-half inch pots, thus ensuring evenness of growth and flower. Lastly, never make the raistnkle of trying to force second quality bulbs. Only the best are good enough for this purpose, for it must ho borne in mind that such artificial culture places a great strain upon the bulbs. They must be of first quality and in perfect health if they are to produce satisfactory results.—A. 11., in Amateur Gardening.