Roger Cook's 'Bulb Sandwich'
To get the most out of a limited amount of planting space, This Old House landscaping contractor Roger Cook likes to make a thick "bulb sandwich." "All you need to do is dig one big hole, then layer in three bulb varieties according to their different bloom times," says Roger. "Crocuses, tulips, and daffodils are a good trio." Spring will bring sequential waves of flowers in the same spot. As the early-blooming crocuses fade, they will be followed a couple of weeks later by fresh-faced tulips, then, in another few weeks, a raft of daffodils. An added bonus: Each plant's new growth will help camouflage the wilting flowers and leaves of its predecessors.
The hole should be 10 inches deep, but can be any size or shape. A 12-inch-diameter planting area, for example, can accommodate 7 to 9 daffodil bulbs. Before putting them in, mix a tablespoon of an 8-8-8 fertilizer with the loose soil at the bottom, then gently twist the hairy, broader root end of each bulb into the dirt to establish good contact; the pointy end will be facing up. Be sure to space the bulbs so they don't touch one another, since overcrowding can stop them from blooming.
After covering those deep bulbs with four or five inches of soil, put in 9 to 12 tulips, which do best five or six inches below the surface. Add another two or three inches of soil, and the planting area is ready for 12 to 15 small crocus bulbs. Fill the hole to the top with more soil and soak the area with water. Keep it moist throughout the fall, then leave it dry until spring. The reward is a four- to six-week-long feast of flowers.