Starting annuals from seed is a great way to save money, especially if you're growing a large number of plants. You can sow many varieties, including sunflowers, cosmos, marigolds, bachelor's buttons, annual poppies, balsam, morning glories, castor beans, and larkspur directly in loose soil in the garden. Or get a head start on the season by sowing them indoors.
Growing transplants in the garden is necessary if you want special varieties that can't be grown from seed or if you start seeds indoors. To plant them, dig a hole at least twice as wide as the container the plant is growing in, but no deeper. Gently loosen and spread apart the roots (especially if the plant is rootbound) before placing the plant in the hole. Then cover the roots with soil and water well.
Test Garden Tip: You can group annuals into two basic categories -- cool season and warm season. Cool-season annuals do best in temperatures under 70-75F, and are best for spring or fall displays (or winter, in the Deep South). Popular cool-season annuals include pansy, viola, nemesia, diascia, osteospermum, and flowering kale. Plant cool-season annuals before your average last frost date.
Warm-season annuals, on the other hand, do best in warm conditions and need to be planted after your last frost date and once the soil has warmed. These varieties do best in summer. Examples include ageratum, angelonia, impatiens, begonia, morning glory, petunia, dusty miller, geranium, nasturtium, and moss rose.More Planting Tips
Water your annuals well after you plant them -- they're most susceptible to drying out the first few weeks after you put them in the ground.
Lay a 2- to 3-inch-deep layer of mulch over the soil around your new plants. This helps the soil hold moisture and prevents weeds from growing.