Here are answers to some of the most common questions we receive about garden plants. You will find concise information on general gardening techniques as well as plant selection and care. For detailed information on specific plant pests and problems refer to our Common Garden Pests and Problems page.

Do you have additional gardening questions? Please contact us. Here's how.

Horticulture Questions and Answers

Home  >  Indoor Plants  >  General Care  >  How do I force bulbs for indoor bloom?

How do I force bulbs for indoor bloom?

Bulbs for forcing indoors fall into two categories: those which need a cool rooting period of several weeks outdoors and those which do not. Those that do not need a cool rooting period include: paperwhites and amaryllis. These are easy to force. All that is required is that the bulbs be potted up and watered sparingly until growth begins. You can pot the bulbs in potting soil or use sand or pebbles. The bulbs should bloom in four to six weeks. For more information on growing amaryllis listen to message 3800.

Bulbs which need a cool rooting period include tulips, daffodils, crocus and hyacinth. To force these you will need to store the potted bulbs in a dark area between 35-45 degrees F. for 12-15 weeks for the bulbs to root. Suitable location can include a cool, dark unheated basement, a refrigerator or an outdoor cold frame or trench.

Buy only top quality large bulbs for forcing. Select low bulb pots and use a good potting soil which has had some all purpose fertilizer such as 12-12-12 added to it. Place several bulbs in each pot for best effect. A 6 inch pot can hold 3 hyacinth bulbs, 3-6 daffodil bulbs, 5-6 tulip bulbs or 8-12 crocus bulbs. Plant with the top of the bulb just at or below ground level. Water well and store in a cool location for rooting. Digging a shallow trench out doors and placing the pots in the trench covered with leaves works well for many gardeners. It is critical that the bulbs stay cool and that the soil in the pots remains moist but not wet. Since fall rains and temperatures fluctuate widely, finding the ideal location out of doors can be challenging. If the pots freeze rooting will stop until the soil warms again.

After 12 to 13 weeks check the pots. If roots have grown through the drainage hole and top growth is about 1 1/2 inches high, the pot can be brought indoors for flowering. You may want to leave some pots outdoors to be brought indoors later. When you bring in the pot place it in a warm dark location for about a week then move it to a bright sunny window and keep moist. In about another week the plant should bloom.

Good varieties of hyacinths for forcing include: 'Pink Pearl', 'Delft Blue', 'L'Innocence' a white, 'City of Haarlem' a yellow, and 'Jan Bos' a red.

Good varieties of tulips include: 'Appledorn' an orange-scarlet, 'Christmas Marvel' a cherry-pink, 'Kansas' a white, and 'Attila' a purple-violet.

Good choices for daffodils are: 'Dutch Master' a yellow, 'Flower Record' a white with orange cup, and 'Mt. Hood' a pure white.

For crocus try 'Flower Record' a lavender, 'Jeanne d'Arc' a white, or 'Pickwick' which is white striped with purple.