Stimulating a bulb to bloom out of season is called “forcing”. Forced bulbs will provide colorful potted plants for your home during the winter months. The bulbs most commonly used for this purpose are daffodils, tulips, hyacinth, and crocus.
When choosing bulbs, look for varieties labeled “suitable for indoor forcing”. Other bulbs can be used, but may give you less reliable results. Plant in containers from late September through November to bloom from Christmas to spring. Most bulbs require a cooling period of about 14-15 weeks.
Plant in well-drained, lightweight soil. Place the bulbs so they almost touch each other and so their tops are even with the pot rim. Fill around them with soil almost to the rim and water well. The bulbs contain all the food they require to be forced, so don’t fertilize.
A 6” pot will hold about 3 hyacinth, 6 daffodils or tulips, or about 15 crocus. When planting tulips, place the flattest side of the bulb facing out. Label each pot with the variety name and planting date.
The bulbs should be cooled to 35-45 degrees. Do not let them freeze. Use an unheated basement, root cellar, or extra refrigerator. The roots develop during this period, so keep the soil moist, but not soggy.
After the 14-15 week cooling period, top growth starts. Once the tops have grown some (about 2” for the larger bulbs), take the pots out of cold storage and bring them into 60 degree temperatures and bright light. It should now take about 2-3 weeks for blooms to appear. Rotate the pots regularly to promote even growth. Keep the blooms out of direct sunlight so they last longer. Keep the soil somewhat moist.
See the Dundee Fact sheet about Amaryllis to learn more about growing those bulbs indoors.
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