Tips for growing bulbs
Sept./Oct. 2012 California Bountiful magazine
Unlike seeds, bulbs (along with their cousins tubers, rhizomes and corms) are not dormant and dry. They are in a slightly suspended state, and the sooner you get them in the ground where they can form roots and grow, the better.
Size: Pick the biggest ones because they generally produce more flowers.
Freshness: The best bulbs look fresh, much like produce at the grocery store. They should have some heft to them when you pick them up and not feel spongy, withered or dry. They should be firm to the touch, full of moisture.
Appearance: The skin on tulip, hyacinth and daffodil bulbs comes off easily, so don't worry about that. Also don't be concerned if there is a bit of mold on the surface. But don't buy bulbs already beginning to sprout. Usually this means the bulb has been kept at room temperature too long, and this signals the bulb to grow. If you buy bulbs already sprouting, get them in the ground as soon as possible.
Planting depth: Each bulb has a recommended planting depth. This is measured from the top of the bulb. At the correct depth, bulbs get the right amount of moisture and air to thrive. Too shallow and they are subject to swings in moisture and temperature. Too deep and they can suffocate or spend too much energy trying to reach the surface. Generally, you want to plant a bulb two to four times as deep as the bulb is tall. This means daffodils will be planted 4 to 6 inches deep, hyacinths about 4 inches deep and Dutch iris about 2 inches deep. The exception is the bearded iris, which likes to be planted with its top showing. Remember, too, each bulb has a top and a bottom. If there is a pointed end, it faces up.
Planting times: Bulbs appear on nursery shelves in spring and fall, depending on the type of bulb. Buy early and plant as soon as possible. Scott Kunst of Old House Gardens, which specialized in heirloom bulbs, says, "If you plant them, no matter how late, there's always a chance for them to bloom. But if you don't, they surely won't."