Autumn to early winter is the time to plant daffodils, crocus, tulips, hyacinths and other spring-blooming bulbs. Wait until the soil temperature at the planting depth has fallen below 60 degrees. In general, October is recommended for Zone 6 and November to early December in Zones 7–8. However, bulbs can be planted any time before the ground freezes hard and soil can still be worked. Depending on the species and variety, bulbs need a cold period of 6 to 20 weeks. Choose firm, healthy bulbs. If you can't plant them right away, keep them in a cool location (50–65 degrees F) until planting.
The hardiness of dahlias, gladiolus, cannas and elephant ears varies, and gardeners are often undecided about whether to leave them in the ground or to lift bulbs and store them for replanting in spring. Survival depends on many factors: the average minimum winter temperatures in your area, the severity of a given winter, the degree of shelter in your garden, and the species or cultivar. Bulbs are ranked from the most tender (injured below 68 degrees F) to the hardiest (injured below 5 degrees F). The USDA Plant Hardiness Zone Map delineates three growing zones for North Carolina (6, 7 and 8). Cannas may remain in the ground, mulched, in Zones 7 and 8. Lift rhizomes in Zone 6 after first frost. Glads and elephant ears are usually safe within Zones 7 and 8, but again, conditions vary. If in doubt, lift and store.
Tired of planting hybrid tulips again and again? Try species tulips, which are true perennials that multiply rapidly. The cheery flowers are available in an array of solid or bicolor shades; they are starlike or cup-shaped, and a single stem often bears several flowers. Most varieties are shorter in stature than hybrids. Plant your bulbs when the ground has cooled to about 60 degrees, usually by November or December.
Plant garlic from mid-September through November, depending on your location (on the earliest side of the range in the western parts of the state). Garlic needs adequate time for roots to develop before winter and about a 2-month cold period for robust bulbs to form in spring. Spring planting is least optimal.