Van Dycks

Garden Guide Indoor (forced) Bulbs

Forcing bulbs indoors is a process by which you get the bulbs to flower earlier than they would if planted in the garden. When forcing, bulbs are potted, then subjected to darkness and temperatures near freezing for several months to mimic outdoor conditions. When there is sufficient root growth, they are brought gradually into the heat and light as if they were emerging on a balmy spring day. Some bulbs, like Amaryllis and Paperwhite Narcissus are not hardy outdoor bulbs and do not need to go through a cold period to force them into bloom.

For forcing, use only named varieties of bulbs and top-sized bulbs. Avoid bulb mixtures that may be suitable for naturalizing outdoors; indoors they will be disappointing. To guarantee flowering bulbs throughout the winter, choose a variety of different bulbs, and make successive plantings through the fall.

Keep all bulbs away from apples or pineapples which give off ethylene gas that inhibits flower formation.

Bulbs as Houseplants
Several of the summer bulbs do well as houseplants.
Planting & Forcing Steps
In order to enjoy beautiful blooms in winter, you must make plans in late fall.
Forceable Bulbs

Alphabetical Index

Varieties

Amaryllis
See Hippeastrum
Amazon Lily
See Eucharis amazonica grandiflora
Blood Lily
See Haemanthus
Chinese Sacred Lily
See Narcissus
Clivia minata

(Kafir Lily) In warmest areas, Cliviacan grow outdoors. Plant 18-24" apart in partial shadein well-drained, acid to neutral soil. Grows 18-24"tall. Blooms February-May. Hardy in zones 10-11, other must plant inside. Indoor Culture Clivia is an excellent potted plant. Plant with the root system just below the soil line inrich, well-drained soil. After planting, Clivia shouldnot be disturbed. It is happiest when rootbound. Provide bright, indirect sunlight and good air circulation. Keep the soil moist; feed regularly. In November, when growth slows, water less frequently. Clivias canbe moved outside to a shady spot for the summer.

Crocus Pot

The pre-potted, pre-cooled Crocusbulbs will bloom in their attractive pot within two tothree weeks after arrival. Simply water the bulbs threetimes a week. When blooming starts, keep the CrocusPot in the coolest part of the room away from radiatorsor direct sun. You can prolong flowering by keepingthe Crocus in a cool room at night. When theflowers fade, water bulbs only once every two weeks. When the weather warms in spring, remove the bulbsfrom the pot and plant outside. They will lie dormantduring the summer and winter, then bloom again inthe garden for your enjoyment the following spring.

Eucharis amazonica grandiflora

(AmazonLily) Plant the bulb in a rich, open soil mixture, 3-4bulbs per 8" pot. Leave the neck of the bulb exposed. Mist frequently to maintain high humidity. Grow inbright shade with a minimum night temperature of65-70°. For several weeks, lower the night temperatureto 55-60° and cut back on water until the leavesdroop. Go back to regular night temperature andwater generously. This induces flowering, which willoccur in several months. Keep the plant potbound forbest flowering. Do not repot more than once every 2-3 years. Grows 20-24" tall. Hardy in zone 10.

Haemanthus

(Blood Lily) Plant the bulbs in 6" containersas soon as they arrive in the spring. Set thebulb in well-drained potting soil so the bulb tip is atthe soil surface. Place container in a sunny to partiallyshaded location and keep soil moist, but not waterlogged. Leaves and the flower stem will appear within12-16 weeks after planting. Remove spent flowerstem after blooming. In the fall, start withholdingwater and allow foliage to ripen before removing. Store bulb in container in a cool, dry, frost-free locationover the winter. Do not repot. They grow andbloom best when pot-bound. Then, in the late spring, bring container into a cool, sunny location and beginwatering. New growth will appear and the growingcycle starts all over. Grows 10-12" tall. Blooms 12-16weeks after planting. Hardy in zones 9-10.

Hippeastrum

(Amaryllis) Amaryllis thrive whenthey are potbound. Choose a deep pot that is notmore than 2" wider than the bulb. Using good pottingsoil, plant the bulb so that the upper 1⁄3 of the bulb isabove the soil level. Water thoroughly, then place in full sun at room temperature (65-70°). Water onlywhen the soil feels dry to the touch. It will bloomwithin 6-8 weeks. After the flower fades, cut downthe flower stalk. Continue to water. Fertilize once amonth. During the summer, plant the pot and bulb inthe garden. In September, bring the pot and bulbindoors, and start withholding water. Let foliage dry. Store in a cool dark place with no water or fertilizerfor 8-10 weeks. In mid-November, add some freshsoil and start re-watering.

Lilium

(Lily) Use only bulbs that have been precooledfor pot culture. Make a light, porous pottingmixture for lilies using 2 parts sandy loam, 1 partsphagnum moss and 1 part sand. Large, deep pots areessential. Plant 3 bulbs in an 8-10" pot. Deep plantingis important. Put the pots in the greenhouse orbright sunny room immediately. Lilies need day temperaturesof 68° or less and night temperatures of 40-50°. Do not force at temperatures higher than 70°. Fertilize with a 5-10-5 liquid fertilizer when the budsfirst appear and then 14 days later. Plants will flowerapproximately 30 days after the buds first become visible. You can then increase temperature for fasterblooming or decrease temperature to slow thegrowth. The forced bulbs can be planted after bloomingin your garden for added years of pleasure.

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