Pruning tulips and other spring-flowering bulbs, helps ensure the best flower production, season after season. Pruning spring-blooming bulbs involves two steps: clipping spent flowers and removing faded foliage. Timing is important in both steps of the pruning process. In step one, it’s important to cut back tulip, daffodil and hyacinth flowers once they begin to fade. Left on the stem after the flower wilts encourages the bulb to produce seed. As a rule, tulips don’t reproduce well from seed so allowing a seed pod to form takes away energy from the bulb unnecessarily. Snip the flower all the way to the base of the stem, but don’t remove any foliage at this time. Tulips, as well as daffodils and hyacinths, depend on this green foliage to replenish each bulb for next season’s flowering. Removing the foliage too early means fewer and smaller blooms next season, if any. It isn’t necessary to prune smaller bulbs such as muscari or crocus.
Once you’ve removed the spent flowers, apply a mild fertilizer to the bulb bed. This will help restore nutrients used up in the blooming process.
Leave the foliage in place as long as it is green. It usually takes about six weeks after the flowers fade for the foliage to start to turn yellow. Once it does, cut the foliage back hard to the ground. Follow this process if you’re treating your bulbs as perennials; that is, you expect them to come back year after year and flower well. Some gardeners treat bulbs as annuals and dig them up each spring after the blooms have faded. This is done in order to utilize the space for planting summer-flowering annuals. Either practice is acceptable, but to get the best production season after season, it’s important to remove spent flowers first, followed by foliage pruning some six weeks later.