November 4, 2002

By now spring bulb planting should be well underway, if not finished. The rain in October may have delayed bulb planting somewhat, but try to get those bulbs in the ground soon. They need some time to grow roots before winter arrives.
Another way to enjoy the spring flowering bulbs such as crocus, hyacinth and tulips is to force them to bloom indoors during the winter months. To do this, the bulbs are potted up in containers that are then put through a chilling period for at least 12 weeks. During this time the bulbs develop roots, stems and flower buds.
Choose containers of metal, ceramic, plastic or clay. New clay pots should be soaked for 24 hours prior to planting. Bulbs require well-drained soil, so make sure the container has a drainage hole. The container should also be twice as deep as the bulb for adequate root growth. Use a lightweight potting mix and there is no need to add fertilizer. A bulb contains all the food it needs for growth.
Fill the container almost full with the potting mix. Then plant the bulbs on top very close together, adding a little more soil to just hold them in place. Water carefully, enough to moisten the soil without it becoming too soggy. Now they are ready for cold storage.
There are several locations that are good places for chilling the planted bulbs. The pots can be dug into the garden and mulched in to cover. A cold frame is also an ideal place to put the pots. Alternatively, the pots can be kept in an unheated garage or basement where the temperature can remain below 50 degrees for at least 12 weeks. Water to keep the soil moist when necessary.
After 12 weeks of cold storage, the root system should be well developed and one-inch sprouts should be growing from the top of the bulb. That means the bulbs are ready to come inside. Move them indoors to a sunny location and where the temperature doesn't exceed 80 degrees. Any pale shoots will quickly green up in the bright light. Water as you would any houseplant.
Daffodils, tulips, hyacinths and crocus can all be forced into bloom this way. But most of the lesser-known bulbs can also be used, especially the smaller varieties. Sometimes you can find pre-chilled bulbs ready for forcing. Hyacinths are often sold this way. If they are marked pre-chilled you can start growing them indoors immediately.
Right now for the holiday season it is easy to find paperwhite narcissus and amaryllis bulbs for growing indoors. There is no need to pre-chill either of these bulbs. They can be potted up in the same manner as the bulbs previously mentioned. The paperwhites can also be set in a dish of pebbles or marble chips, without using any soil. Add water to below the level of the base of the bulbs when setting them in stones. The roots will find the water and the bulb will not rot.
Amaryllis are extremely showy bulbs, available in many colors from red to white and various shades in between. Double and dwarf varieties are also popular. They can be potted into a container that is an inch bigger than the bulb itself. Another way to display them is to set the large bulb into an appropriately sized bulb vase. The vase is filled with water to just below the base of the bulb. These vases can also be filled with decorative stones that will hold the developing roots. Bulb vases can be used to grow a single paperwhite or hyacinth as well.
Paperwhites will usually begin blooming a month to six weeks after planting. Their fragrance will fill a room with a perfume scent. Amaryllis will bloom in 6-10 weeks from the time it is potted and watered. Turning the pots regularly will keep the plants growing straight. And a cool room temperature will give optimal results. Paperwhites may need to be staked if they grow too tall. Both the paperwhites and the amaryllis can be planted in time for holiday blooming.

Beth Nardone, botanist, is a resident of Hillsborough and is the Nursery Manager at the Belle Mead Co-Op. Questions and comments can be sent to bethtanical@rcn.com