Growing Narcissus Bulbs
Growing Narcissus Bulbs
For early flowering, pre-cooled bulbs (double nosed I, II and III are generally used for forcing) are purchased, these having been given four days of heat at 33°C (93°F), followed by 17.2°C (63°F) for one or two weeks, then cool stored at 7.2°C (45°F) until planting. Bulbs for later flowering are given 17.2°C (63°F) till the flower is complete in the bulb, then stored at 8.9°C (48°F). Variations in temperature treatment are also used to influence flower size.
Planting Narcissus bulbs in borders
Bulbs can be grown either directly in borders, or planted in boxes, bowls or pots. Any goodwith a pH of about 6 and a reasonable nutrient content will suffice. Planting direct into greenhouse borders is done in mid-autumn, in rows 15cm (6in) apart, the bulbs spaced 5-7.5cm (2-3in) apart in the rows. Water in well and cover with straw. Keep as cool as possible by ventilating for 6-7 weeks, then raise temperatures in steps of 2.6-5.5°C (5-10°F) to around 18.3°C (65°F). Keep bulbs well watered, about 75litre/m2 (15 gallons per sq yd) being necessary.
Planting Narcissus bulbs in boxes
Push the bulbs into deep 12.5-15cm (56in) boxes of clean soil which has not grown bulbs before, pH adjusted to 6.25, leaving the bulbs with their noses clear. Cover with a layer of sand or other material to act as a barrier between the soil or peat which will be used to cover them in a plunge out of doors to minimum depth of 15cm (6in). This is generally achieved in the first week of mid-autumn and adequate watering should be given to induce lower temperatures (by evaporation) down to about 7.2°C (45°F).
Boxes are brought into the greenhouse from the late autumn until late winter according to variety, whenare clear of the neck of the bulb and there is good root development, and not before (suppliers’ catalogues should always be consulted for housing dates). Minimum heat is given for 7-10 days, the temperature gradually being raised to 18.3°C (65°F). Water the boxes as necessary and make sure that they get all the light they need, otherwise the leaves will become gross. Support may be provided with netting or broken canes and string.
Bowls or pots of bulbs should be treated in the same way, strict attention being paid to watering and the amount of light given. Bulbs for later flowering should be left longer in the plunge and given lower temperatures in the greenhouse or home.
Forcing Narcissus bulbs under artificial light
This is carried out in the same way as described for tulips (below) although in general it is better to have higher light levels and lower temperatures 15.6°C (60°F), taking 4-6 weeks on average for the bulbs to flower.
Pests, diseases and troubles
Narcissi are not difficult to grow, but they can suffer from a number of troubles.