Growing Narcissus Paperwhite
Upon arrival, before starting the protocol, it is necessary to put the bulbs in exactly 25C in a well ventilation area.
Putting the bulbs in 25C from harvesting till forcing ensures at least 2 flowers stems per bulb.
Force the dry bulbs at 17C for 3 weeks.
Insure that the humidity will not be more then70% to prevent rooting in the cooling room. If yes, plant the bulbs immediately.
Week36 is the earliest time for planting forced bulbs.
Planting: Use a well drained, PH 5.5-6, sterilized planting medium.
Plant 3 bulbs in a 12cm diameter pot, 5 bulbs in a 15cm diameter pot, or 7 to 9 bulbs in an 18-19cm diameter bulb pan.
Spacing on Bench: Grow plants pot to pot.
Watering: Keep the planting medium moist, but not over watered.
Light: Use a medium (greater than 2500 foot candles) light intensity greenhouse.
Temperature: Use 10-12C night and 18-20C day temperature greenhouse.
Lower temperature can be used, but the plants take longer to reach the market stage.
Normally, this is 3 to 5 weeks.
Ventilation: Use a well ventilation greenhouse.
Fertilization: Plants are fed on a constant basis with a solution of 14-5-14 at a rate of 1 lb. per 100 gal. water. Phosphoric acid was added at a rate of 1 to 1 1/2 oz. per 100 gal. to provide an irrigation pH of approximately 5.5.
Diseases and insects: Normally, diseases and insects are not a problem. However, forcers should always inspect for Botrytis and Aphids.
Marketing, Storage and Transportation
Forces: The flowers should be marketed when the shoots are 20-25cm tall, the floral stalks are visible, but the flowers are not open.
To store plants, place at 5C.
Wholesalers and Retailers: market “paperwhite” in the “bud” stage of development. This ensures the consumer will receive maximum satisfaction of the flowering potted plant.
- Early flowering:
15th August – Forcing the dry bulbs at 17C for 3 weeks
1st September – planting the forced bulbs
Mid-End October – flowering time (approximately 45 days in greenhouse)
- Christmas flowering:
1st October – Forcing the dry bulbs at 17C for 2 weeks
15th October – planting the forced bulbs
Mid November – Flowering time (approximately 30 days in greenhouse)
- Late flowering:
Bulbs can be planted also after January however for late planting it is necessary at beginning of September to increase the temp of the stored bulbs from 25C to 30C.