Adequate drainage is an important consideration. Most bulbs and bulb-like plants will not tolerate poor drainage, and rot easily if planted in wet areas. Function must also be kept in mind. If bulbs are being used to naturalize an area, toss the bulbs then plant them where they fall to create a scattered effect. Spanish squills will do beautifully along with daffodils to achieve a natural effect.
Good drainage is the most important single factor for successful bulb growing.
Bulb beds should be dug when the soil is fairly dry. Wet soil packs tightly and retards plant growth. Spade the soil 8 to 12 inches deep. As you dig, remove large stones and building trash, but turn under all leaves, grass, stems, roots, and anything else that will decay. Add fertilizer and organic matter to the soil.