Forcing Bulbs

Forcing is the process of hastening a plant to maturity, or of growing it to the flowering or fruiting stage out of its normal season.

Only top quality, mature-sized bulbs should be used.

Forcing in Soil

Begin in October by potting the bulbs in clean, sterile, plastic pots. Do not bury the bulbs. The “noses” (where the leaves come out) should be exposed.

High quality potting soil is acceptable, or mix equal parts potting soil, coir fiber, and perlite or vermiculite for best results.

Plant the bulbs close together in the pot. Usually 6 tulip bulbs, 3 hyacinths, 6 daffodils, or 15 crocus, will fit into a 6-inch pot.

The flat side of the tulip bulb should be placed next to the rim of the pot since the largest leaf will always emerge and grow on that side, producing a more attractive looking pot.

It's extremely important that bulbs be handled with care at all times. Never allow the bulbs to be in temperatures above 65 degrees F.

When planting, the pot should be loosely filled with soil. Don't press the bulbs into the soil. Allow 1/4-inch of space at the top of the pot so it can be watered easily.

The bulbs should be watered immediately upon planting, and thereafter the soil should never be allowed to dry completely.

Forcing in Water

Hyacinths, crocus, and narcissus can be forced in water. Special glass vases are made for hyacinths or crocus.

The bulb is placed in the upper portion, water in the lower portion. The vase is then kept in a cool, dark room (preferably under 50 degrees F) for four to eight weeks until the root system has developed and the top elongates. At this point it should be placed in a bright window, where the plant soon will blossom.

Bunch-flowering narcissus, such as Paperwhites (Narcissus tazetta) can be grown in shallow dishes of water filled with crushed rocks, pebbles, marbles, or other media. The bulbs should be secured in the medium deeply enough so the basal plate (where the roots come out) is in contact with the water.

Keep them in a cool, dark room for several weeks to ensure root growth, then place in a sunny location. Each bulb will send up several flower stems bearing many tiny blossoms.

Preventing tall growth

If your paperwhites usually grow too tall, flop over, or need staking, water them with a little drink of alcohol to stunt their height by half to a third. Details below.

Begin by planting your paperwhites in gravel and water the normal way. Once the shoots are about two inches tall, pour out the water you used to start them. Replace that with a solution of water and alcohol. Use this solution instead of plain water from now on to top up your container.

To achieve the proper proportion, you can use isopropyl alcohol (rubbing alcohol) with water mixed at one part alcohol to ten parts water.

Discard these plants after flowering. They are spent and will not bloom again.

Bulbs Good for Indoor Forcing:

  • Amaryllis (Hippeastrum species
  • Crocus
  • Grape Hyacinths
  • Hyacinths
  • Lily of the Valley (Buy in Spring)
  • Daffodils (Narcissus)
  • Paperwhites (Narcissus tazetta)
  • Scillas
  • Tulips