The key to a beautiful bulb flower bed is lots and lots of bulbs. Following is a general idea of the number of bulbs you should buy per square feet of flower bed size.
Planting one straight row of evenly spaced bulbs often looks sparse. Planting in quantity in non-linear patterns will always give a richer appearance. This is why mass planting has always been the traditional way to use bulbs. Mass plantings can include dozens or even hundreds of bulbs - especially if you do a naturalizing project. If you don't have room for mass planting, or need to start small, a reliable way is to plant in clumps of 6 or more bulbs. This is a very attractive method for hyacinths, daffodils and tulips. In the clump, space your bulbs about 4 or more inches apart. If you are ready to try true mass planting.