Care for the potted tulips as normal until the green foliage begins to turn yellow. Do not prematurely remove the green leaves or you will stop the production of food for next year's plants. Remove the spent flower stalks, though, by clipping them off. Keep the tulip plants in a sunny location and the soil moist. Fertilize them after blooming with a bulb fertilizer, following the directions and dosages written on the label.
Stop watering the tulips when the leaves begin to turn yellow. Once the leaves dry out, remove the spent foliage by either gently tugging them from the bulbs or clipping them off at soil level with garden clippers. Do not remove the bulbs from the pot.
Place the potted tulips in a cool location, such as a garage or basement, to keep until fall. If it is winter and the ground is frozen, store the tulips in the cool location until the ground thaws and you can work the soil to plant them.
Dig the bulbs out of the pots with your hands. They are most likely planted just below the soil line. Examine the bulbs and if any are shriveled, damaged or decaying, throw them out.
Dig planting holes outdoors in a sunny area of your garden using a trowel. Make the holes deep enough so that the pointy tips of the bulbs will be planted 6 inches below the soil line. Space the holes 4 to 6 inches apart. Place one bulb in each hole -- with the pointy side up -- and pack the soil gently around the bulbs to fill in the hole.
Water the bulbs with 1 inch of water about once a week until rainfall sufficiently meets their watering needs.