Should ALL the foliage on spring-flowering bulbs die back before being cut off, or can it all be cut off when the leaves are one-half brown?

A common mistake with spring-flowering bulbs is to remove the foliage prematurely. When tulips and other spring bulbs bloom, they consume, and quite often exhaust, the built-up food reserves stored in the bulb. If the bulb is to have any chance of blooming the following spring, the foliage should be encouraged by fertilizing (with something like Holland’s Bulb Booster) and left in pace until it completely dies down. Because you want to direct as much energy as possible into bulb-building, remove the flower stems when the flower petals have fallen. Allowing the spent flowers to go to seed will only further divert energy from next year’s bulb production.