What to do with those green leaves once the blooms are done:
Deadhead all spend blooms as they take energy from the bulb to produce seed.
Leave the foliage up as long as possible as this is how the bulb builds up its food for next year's bloom.
Recent research from Holland seems to indicate that the leaves really only have to stay up for about 5 weeks past bloom.
My experience has been that it does not cause any problems when tying the leaves together in a bunch in order to make room for annuals to be planted. It also does not seem to suppress the manufacturing of food for next years' bloom.
Should bulbs be fed at this time:
Yes. Feed them when they are done blooming, while the green leaves are still up, with a granular fertilizer. It's best to use an organic one such as Bulbtone or bone meal. We have everything you need in stock at McArdle's.
Some gardeners like to feed them prior to bloom. Should use a water soluble fertilizer at this time such as fish emulsion. Call me at McArdle's (203-661-5600) or stop in to see me for a personalized recommendation.
Can gift pots of bulbs from the recent holidays be planted outside for bloom next spring:
Yes. There are several ways this can be done, but most important is that these bulbs be fed. Forcing bulbs takes a lot of energy (food) out of a bulb. If they are not fed, their blooms will be small or they may not come back at all. Even with feeding they may be weak.
One of the best ways to get them to come back is to leave them in the pot and water and feed them until they start to go yellow. Let the green tops turn brown and dry out naturally. Then take them out of the pot, remove any dirt, and store them in a cool and dry place until the fall. In the fall, plant them in the same manner as newly purchased bulbs.
Some gardeners just plant them right from the pot, into the garden, placing them at the proper planting depth. Keep them watered and fertilized in the garden.