Annuals can be used to fill gaps in the blooming sequence of perennial plants and are more desirable in unprotected planters in which perennials could not survive the winter. Some annuals are mistaken as perennials because they can self-seed easily. Set out as bedding plants, annuals provide nearly instant gratification and feelings of pride and success. They also provide the opportunity to learn a wide range of cultural skills. Although annuals are associated with summer, activities based on annuals can continue throughout the year with such indoor practices as starting seed, dried flower arranging, and garden planning.
Snapdragons prefer the cool, moist parts of the growing season.
Treated with care and snipped back, these plants can be helped through the hot summer months to thrive again in the fall. Portulacca, on the other hand, is a fleshy annual which seems to thrive in the hot, dry weather. Zinnias are also heat tolerant and bloom in late summer and fall. Breeders have developed dwarf varieties of zinnias for the small garden. These are better for raised planters than older varieties which tend to get leggy.