Crop-Specific Guidelines for Growers

Daffodil, Narcissus sp.

About Daffodils

Narcissus (daffodil, jonquil) is a genus of spring-flowering true bulbs originating in Spain and Portugal. Although Narcissus only became commercially important in the late 1800's, they had been cultivated for centuries before that time. As a result of this long horticultural history, there are now approximately 18,000 distinct cultivars, as well as many wild species. To make some sense of this bewildering quantity of plants, the genus has been subdivided both horticulturally and botanically. The hybrids of N. pseudonarcissus are the most commercially important daffodils. Daffodils are sold as dry bulbs for planting in the garden, where they may naturalize and persist for many years, as cut flowers, and as potted plants. In the southern U.S. certain Narcissus species and cultivars are among the few Dutch bulbs which can be successfully perennialized, even in very warm coastal climates.

Forcing

Daffodils are forced for three different markets: the early cut flower market, the regular season cut flower market, and the potted plant market. Plants grown for these three purposes must be treated differently. In addition, the paperwhite narcissus N. tazetta, does not require a chilling period, and so follows a different schedule for pot and cut flower production.

EXTRA-EARLY FORCING OF CUT NARCISSUS (used mostly in the United Kingdom)
For cut daffodils, extra early forcing requires a precooling treatment beginning in the summer. Bulbs are usually lifted in early June, and briefly exposed to high temperatures 95 F (35 C ) for 5 days to insure floral bud differentiation within the bulb. The bulbs are then held at about 62.5 F (17 C) or ambient temperatures until the flower primordia reach the paracorolla (Pc) stage. The Pc stage is the point in the development of the flower primordia within the bulbs at which the corolla (trumpet) is visible in a dissected bud. Upon reaching the Pc stage, the bulbs are given a precooling treatment of 48 F (9 C) for 6 weeks. In August or September the bulbs are planted, and are chilled in the rooting room for 6 more weeks at 48 F (9 C). Finally, they are moved to the greenhouse for forcing, usually arriving at full bloom within the month, around 20 November. The cut stems are harvested in the gooseneck stage, and stored upright, dry, at 32 - 35.5 F (0 - 2 C) with over 90% relative humidity.

FORCER'S SCHEDULE FOR EXTRA-EARLY CUTNARCISSUS:
At paracorolla stage - 48 F (9 C )for 6 weeks (precooling)
August to mid-September - pot and hold in rooting room for 6 weeks at 48 F (9 C)
October/November - move to greenhouse for forcing
November - harvest

REGULAR SEASON FORCING
The regular season for cut Narcisssus runs from mid January to mid-April. Prior to planting, the bulbs should be stored in a cool, dry environment. Bulbs should be inspected for disease and damage, and then given plenty of ventiliation. After potting, Narcissus should be held at low temperatures 48 F (9 C) until 1 - 5 December. Then the temperature must be reduced to 41 F (5 C) until 1 - 5 January. After that, the temperature in the rooting room is reduced to 32 - 35.5 F (0 - 2 C) until the plants are moved to the greenhouse for forcing. This final length of rooting room chilling is determined by the producer's chosen date for harvesting and selling the plants. Also, chilling requirements vary from cultivar to cultivar. Most daffodils need approximately 18 weeks total in the rooting room. The forcing period also varies among cultivars, ranging from 7 to 28 days. General guidelines are given below; for specific cultvar requirements, refer to the Bulb Forcer's Guide. Forcers should harvest the cut stems in the gooseneck stage, and store upright, dry, at (0 - 2 C) with over 90% relative humidity. Retailers should recut the stems at about 1/4" from the end and harden in about 7 inches of lukewarm water. DO NOT harden in the same water with tulips, as the daffodil sap decreases the tulips' vase life.

FORCER'S SCHEDULE FOR REGULAR SEASON CUT NARCISSUS:
Preplanting storage - 55.4 F (13 C) for untreated bulbs or 48 F (9 C) for preecooled bulbs
October - pot and hold in rooting room at 48 F (9 C)
1 - 5 December - reduce temperature to 41 F (5 C)
1 - 5 January - reduce temperature to 32 - 35.5 F (0 - 2 C) until forcing
After moving to greenhouse, harvest within the month.

POTTED NARCISSUS
The market for potted Narcissus is from late December to mid-April. Using controlled temperature rooting rooms and different planting dates allows the grower to produce high quality flowering daffodils throughout that period. There are two chilling schedules for potted daffodils: A and B. Which schedule you follow depends on the desired marketing time for that particular crop of daffodils. It is neccessary to use precooled bulbs to have blooming plants for the very earliest market (late December and January). The optimum length of cold storage varies by cultivar. Crops for harvest from late December through late January need 13 - 16 weeks of chilling, while crops flowering later receive progressively more cold, with a maximum of 23 weeks. Refer to the Bulb Forcer's Guide for the chilling requirements of specific cultivars. Market potted Narcissus at the "pencil stage" before the buds begin to point down.

FORCER'S SCHEDULES FOR POTTED NARCISSUS:
Rooting Room A
48 F (9 C) to Nov 5 or till the roots grow out of the bottom of the container
41 F (5 C) to Jan 1 or until the shoots are about 1 inch tall.
32 - 35 F (0 - 2 C)

Rooting Room B
48 F (9 C) to Dec 1 or till the roots grow out of the bottom of the container
41 F (5 C) to Jan 1 or until the shoots are about 1 inch tall.
32 - 35 F (0 - 2 C)

PAPERWHITE NARCISSUS

Paperwhite narcissus (N. tazetta) are popular, fragrant, white daffodils which are grown for cut flowers and as potted plants. They do not require a chilling period, and are usually stored dry at warm temperatures until they are forced in the fall. Forcers should pot the bulbs immediately upon receiving them, and grow them in the greenhouse at approximately 5000 ft candles, with 60 - 63 F (16 - 17 C) night temperatures. If needed, 2000 ppm Florel can be used to retard the stem length of paperwhites in pots; it should be applied when the shoots are 4 - 5 inches tall. The flower stems should be harvested when the first floret is fully colored, and may be stored at 32 - 35 F (0 -2 C). The potted plants are ready for marketing when the shoots are 8 - 10 inches (20 - 25 cm) tall, and the flower buds are visible, but do not show color. Potted paperwhites may be stored at 35 - 41 F (2 - 5 C). In the lower southern U.S. (zones 9 and 10), paperwhites can be grown outside as perennials.

Planting and Forcing Protocols

Daffodils require a pH of 6 - 7, and a mix low in soluble salts. A lightweight peat mix is desirable. For cutting, the bulbs should be planted close together, and are usually grown in 4" deep flats. About 1/3 of the bulbs should be above the soil surface. Cut flower paperwhites are usually grown bulb to bulb, with around 40 15/16-cm or 16/up-cm sized bulbs per flat. Six-inch pots of daffodils should contain 3 bulbs, and 8-inch bulbs pans hold 5 to 6 bulbs. Certain smaller cultivars, such as 'Tete-a-tete', 'Jumblie', 'Minnow', and 'Jack Snipe', can be grown in 4-inch pots. A 6-inch pot usually holds 4 - 5 paperwhite bulbs, and 7 - 8 paperwhite bulbs can be grown in an 8-inch pan.

The ideal temperature for forcing Narcissus< in the greenhouse is 55 - 63 F. The flower quality is best around 55 F, but the plants grow faster at 63 F. However, care must be taken that the temperature does not exceed 65 F, as this causes a disorder called bull-nosing, in which the buds fail to develop beyond the goose-neck stage. The optimal plant height for potted daffodils is 25 - 35 cm (10 - 14 in), and for cut flowers, at least 14 in. If need be, the stems may be stretched by laying newspapers over the plants for a few days.

Visit Narcissus Pests and Diseases