Here are some of the easiest annuals to grow from seed. Sweet alyssum grows 3 to 9 inches tall and makes for a good edging and bedding plant. If you shear the plants back after the first bloom, a second flush of flowers follows. The flowers often fade, though, in the heat of summer. Some gardeners remove them in the heat of summer, then replant when the weather cools in the fall.
USDA Growing Zones: 5 to 9; usually grown as annualColor Varieties: White; pink, purple, and apricot cultivars also availableSun Exposure: Full sun to part shadeSoil Needs: Medium moisture, well-drained soil
The celosias commonly planted as garden annuals are usually somewhat complicated hybrids of two or more species, but the cultivars are generally categorized into four groups: Plumosa Group: Often called feather celosias or cock’s comb, this group has feathered, bright red flowers. Cristata Group: Cultivars in this group have crested flowers with convoluted ridges that resemble brain corral. Flowers can be red, purple, or pink. Childsii Group: This group, rarely sold at garden centers, has rounded flower heads that resemble twisted balls of yarn. Spicata Group: Cultivars in this group cylindrical pink or rose flower heads with e a metallic sheen. ‘Flaming Series’ cultivars are members of this group.
USDA Growing Zones: 10 to 11; usually planted as an annualColor Varieties: Bright red, pink, purpleSun Exposure: Bright red, pink, purpleSoil Needs: Rich, moist, well-drained soil
There are two forms of annual cosmos: C. sulpherous is an upright daisy-like flower that grows 1 to 3 feet tall, with yellow-orange flowers. C. bipinnatus has delicate threadlike foliage and daisy-like flowers of pink, red, or white. It can grow to 4 feet. Both plants are natives to Mexico.
USDA Growing Zones: True annual; grown in all zonesColor Varieties: Yellow (C. sulphureus); red, pink, white (C. bipinnatus)Sun Exposure: Full sunSoil Needs: Dry to medium moisture, well-drained soil
The seeds inside the bean pods can be collected in the fall for spring planting, but be aware that they are toxic unless thoroughly cooked.
USDA Growing Zones: 10 to 11; usually grown as an annualColor Varieties: Rose purple, white, pinkSun Exposure: Full sun to part shadeSoil Needs: Medium moisture, well-drained soil
For some time, impatiens vanished from garden centers because of downy mildew, a devastating fungal disease that killed virtually all seed stock plants. Recently, however, several disease-resistant cultivars have been developed, so you can once again use this plant freely in your shady garden beds.
USDA Growing Zones: 10 to 11; usually grown as an annualColor Varieties: Pink, red, purple, salmon, orange, white, bicolorsSun Exposure: Part shade to full shadeSoil Needs: Rich, moist, well-drained soil
African marigolds (Tagetes erecta): These have large pompom flowers. The plants can grow to 4 feet, and the flowers can be as much as 5 inches across. Colors are various shades of yellow and orange. French marigolds (Tagetes patula): French marigolds have the longest bloom periods, and the plants tend to be short and bushy. They have purple-tinged stems with double flower heads in yellow, orange, and mahogany, about 2 inches across. Signet marigolds (Tagetes tenuifolia): These look much different than other bedding marigolds, with lacy leaves and small, single, daisy-like flowers. They come in yellow and orange. If you’ve had trouble growing marigolds from seed in the past, try growing some of the French varieties, which are more disease-resistant than the American types. ‘Queen Sophia’ is an All-America winner to try. Seeds germinate in less than a week in warm, moist soil. It takes about 8 weeks for plants to bloom from seeds, so you may want to start them indoors.
USDA Growing Zones: True annual; used in all zonesColor Varieties: Yellow, orange, whiteSun Exposure: Full sunSoil Needs: Dry to medium moisture, well-drained soil; prefers rather barren soil
Morning glories grow quickly when planted directly in the garden, but for a headstart on blooms, you can start them indoors six to eight weeks before the last frost date.
USDA Growing Zones: True annual; grown in all zonesColor Varieties: Purple or blue with white throats; cultivars in white, pink, red, magenta also availableSun Exposure: Full sunSoil Needs: Moist, well-drained soil
Nasturtiums are a complicated group featuring many cultivars derived from hybrids of different Tropaeolum species. There are both low mounding types and vining varieties within this group, so carefully research the types of seeds you buy to make sure you get what you want.
USDA Growing Zones: 9 to 11; usually grown as annualsColor Varieties: Red, orange, yellow, creamy whiteSun Exposure: Full sun to part shadeSoil Needs: Poor to average soil that is slightly acidic
Different sunflower varieties have different growth habits, from about 3 feet to as much as 10 feet—make sure to buy the variety appropriate for your needs. Leave the flower heads in place after they fade to provide food for birds.
USDA Growing Zones: True annual; grown in all zonesColor Varieties: Yellow, orange, red, mahogany, bicolorsSun Exposure: Full sunSoil Needs: Dry to average moisture, well-drained soil
The many cultivars of zinnia are derived from one of several species: Zinnia elegans (common zinnia): Plants 1 to 4 feet tall on hairy branching stems produce flowers ranging from daisy-like single blooms to dense pompoms (depending on variety). Zinnea angustifolia (creeping zinnia): With many low-growing varieties, creeping zinnias also have narrower leaves than the common zinnia. Zinnia grandiflora (Rocky Mountain or prairie zinnia): This group includes small narrow-leaved plants about 6 inches tall with yellow-orange flowers. Zinnea haageana (Haage’s zinnia or Mexican zinnia): These are narrow-leaved plants up to 2 feet tall with 1-inch flower heads containing yellow rays and orange center disks.
USDA Growing Zones: True annual; grown in all zonesColor Varieties: Red, yellow, orange, pink, rose, lavender, purple, green, whiteSun Exposure: Full sunSoil Needs: Moist, well-drained soil
