Caso 5 - Background Information

A bulb is a promise. These "packaged plants" each have a complete miniature plant inside along with its food.

The word bulb loosely describes plants that grow from an underground mass of food storage tissue. True bulbs like tulips and daffodils contain a complete miniature plant surrounded by fleshy scales, mostly carbohydrates to nourish the plant, attached to a basal plate from which roots grow. True bulbs can be either tunicate, with a papery covering such as onion or tulip, or scaly, with no paper covering such as lily.

If a bulb is sliced in half horizontally, you will see rings formed by the scaled leaves. These scale leaves store food for use by the bulb as it grows. An onion is a good example. If you slice a bulb vertically, you should be able to distinguish leaves, stems, and even flower buds. You can use an onion here also or use some of the paperwhite narcissus bulbs that will be used in the planting project.

Planting Paperwhites

Paperwhite narcissus are the easiest bulbs to force for indoor growing projects because they need no special conditions to grow and bloom. They are best planted in a container with no drainage holes. The container can be filled one-third of the way with either pebbles or potting soil. The bulb is then placed in the pot and covered with pebbles or soil. Keep the soil moist or if using pebbles, keep the water level to just below the surface of the pebbles. Place the container in a cool, dark, location for about a week. Move the pot to a well-lighted, cool spot, keep watered, and within 3-5 weeks you should have flowers.

A more challenging project would be to force spring bulbs such as tulips, daffodils, or crocus to bloom indoors. Spring bulbs are typically planted outdoors in the fall where they spend the cold winter not resting, but growing roots. By simulating the natural conditions outdoors, you an coax these bulbs to bloom indoors. Ideally the potted bulbs should be kept at temperatures between 35-45 degrees and in the dark.

A cool cellar, unheated garage, refrigerator, or buried outdoors under leaves works well. Check every so often to be sure the soil doesn't dry out. Leave bulbs in these conditions for about 10-12 weeks. By this time the pot should be full of roots and shoots will have emerged. Bring the potted bulbs into a cool, dark area and note the white shoots change color from white to green as it starts to photosynthesize. Move the pot to a bright location and chart the growth of leaves and flower stems. You should have blooms in 2-3 weeks.