The best time to plant bulbs depends on both the type of bulb and the region of the country in which you are planting. The two main types are spring-flowering bulbs and summer to fall flowering bulbs. Spring-flowering bulbs are generally planted in the fall. Popular varieties include tulips, crocuses, and daffodils. Bulbs that flower in the summer and fall are usually more tender, and should be planted in the spring. Common summer and fall bulbs include dahlias, lilies, and gladiolas. Each species of bulbs needs to be planted at specific depths, so be sure to find out the necessary depth before planting. True bulbs will produce smaller bulbs that can be dug up, pulled off, and replanted. Tuberous bulbs, on the other hand, need to be cut and replanted, making sure that each piece has an eye, similar to the growths on a potato. For more information on when to plant bulbs, consult a nursery in your area.