Spring bulbs, such as daffodils, tulips and crocuses, are typically planted in the fall, remain underground during the winter and bloom in the spring. In order for spring bulbs to bloom, they need to be cold for many weeks so they can grow their roots. If you are planning on planting your spring bulbs indoors, you'll be able to plant them any time of the year and enjoy their blooms a few months afterwards, even in the dead of winter. However, you must expose your planted bulbs to necessary cold temperatures. The process of growing bulbs inside is commonly referred to as forcing bulbs.
Select a pot with drainage holes, and make sure it's at least six inches deep. Fill it with "soil-less" potting mix--available at most local nurseries--until it is about 4 to 6 inches from the rim. Layer some gravel on the bottom of the pot first to help with water drainage.
Place the bulbs on top of the soil so they are close together, but not touching. Forcing spring bulbs requires different planting depths and spacing than outdoor bulbs.
Add more soil on top of the bulbs, but only enough to cover the bulbs halfway. Half of each bulb will be under the soil and the other half above the soil. Water the bulbs well.
Store the planted pot in a cool location (between 40 and 50 degrees F) for 10 to 12 weeks. A cool garage, attic or crawl space are good locations. You can also put the pot in an open plastic bag and place it in the refrigerator.
Check on your bulbs every couple weeks to be sure the soil is still moist. Bulbs in the refrigerator tend to dry out faster than bulbs stored in other locations.
Remove the pot after 10 to 12 weeks and place in an area of your home that is warm, but not in direct sunlight. After a few days, when green shoots appear, move the pot to a sunny location in your home and water only to keep the soil moist, not saturated.