Part of why they don't bloom the following year, I think, is because that bed becomes an annual garden in the summer. So the tulips kinda get the "bum's rush" once I buy the annuals, and I cut their leaves down before they have time die off.I sure wouldn’t dig them out. Let them die off, give the spot some fertilizer or bone meal and add in some new bulbs in the fall. Throw a little of the bone meal In the bottom of the hole with the new ones and you should have a great show next spring.