Forcing Bulbs for Indoor Blooms
By Amy Witt, Horticulturist, University of Maine Cooperative Extension

To successfully force bulbs, you need to mimic the process the plant would undergo outdoors in the garden. Many bulbs can be forced including crocus, muscari, tulips, daffodils, and hyacinth. Select bulbs that are large in size, firm, blemish free, and have no sprouts.

How to force bulbs:

• Select containers with good drainage.
• Use potting mix (combination of peat moss, potting soil, sand, vermiculite or perlite), not garden soil. Unlike potting mix, garden soil is heavy and does not drain well.
• Moisten mix thoroughly.
• Fill pot half full with potting mix.
• Fertilize if transplanting outdoors after forcing (1 teaspoon of 5-10-5 to every quart of soil).
• Add a small amount of bone meal.
• Place bulbs’ pointed ends up and flat sides facing edge of container.
• Add more potting mix, until only the upper tips of the bulbs remain slightly exposed.
• Water thoroughly.
• Label the pots with the bulb name, planting date, and removal date.

For proper leaf and flower growth, the bulbs need to go through a cooling period. Depending on the type of bulb, the cooling period can last from 11 to 15 weeks. To ensure proper cooling, place the pots in a cool, dark place (35-48*) and keep the soil moist.

Remove bulbs from cold storage when shoots appear 2-3 inches above the soil and fine white roots have emerged from the drainage holes. Move pots indoors to a cool location (50*) with indirect sunlight. Keep the soil moist and feed bulbs weekly with 1/2 strength solution of houseplant fertilizer. Turn the pots daily to keep the stems straight and strong. When the foliage and buds are well developed, the pots can be moved to a bright, sunny window.

Once the bulbs have finished flowering, cut back the flower stems, stop watering, and keep the plants in direct sun until foliage dies back. Store bulbs in pots in a cool, dry place until they are ready to be planted in the garden in the late summer or early fall.

Planting times: