10 Traditional Annual Flowers to Start from Seed
Nasturtiums (shown) + 9 more.
Starting annual flowers from seed is a good way to save money and to increase your options of flower type and color. (Read more about gardening with annuals, especially seed-started annuals, here.) Here are my top 10 classic annuals to start from seed. (Some of these are technically tender perennials treated like annuals.)
Marigold (Tagetes):
French marigold (T. patula) is the low-growing, familiar type. Their colors reside on the yellow, orange and red side of the color wheel, which makes them great foils for plants with purple flowers. Tagetes erecta is the African marigold, which not only grows much taller than its cousin — up to 48 inches — but also offers cultivars with large white blooms. Both types want lots of sun, fertile soil and regular watering.
Calendula (Calendula officinalis):
Also called pot marigold, calendulas present chrysanthemum-like yellow to orange blooms from summer to fall. Best for cooler, less humid regions, they are easily grown in average soil in full sun, though a little late afternoon shade helps them thrive. It’s best to pinch young plants to promote bushiness and do some deadheading to keep them flowering.
Cosmos (Cosmos bipinnatus):
The saucer-shaped flowers of cosmos top erect stems one to four feet tall. These butterfly magnets come in shades of red, white and pink, with yellow centers. Direct sow just before the last frost date or start them indoors six to eight weeks before that. Space them close so they can support each other, and avoid windy sites. An average, well-drained soil is best. Don’t feed them or they will flop.
Nasturtium (Tropaeolum majus):
This popular sprawler is perfect for direct sowing in poor, slightly acidic soil in full sun. It will tolerate dry conditions if given afternoon shade. Spice-scented flowers of red, orange, yellow or cream appear in spring and keep coming until fall. Famous for their self-sufficiency, nasturtiums readily self-seed, so once you plant some you may find volunteers in your garden for years to come.
Sweet pea (Lathyrus odoratus):
Smell a sweet-pea flower and you’ll want to grow one in your garden every year. This fragrant climber blooms in every color except yellow and can reach eight feet or taller if given adequate support on a trellis or tuteur. Rich soil is best, with some mulch around the roots to keep them cool. Sweet peas perform poorly in hot, humid conditions. In mild-winter regions, they can be direct sown in autumn for flowering in the new year. The best way to do that is to simply let existing plants self-seed.
Sweet alyssum (Lobularia maritima):
Grow this low spreader in full sun or part shade, where the clean white flower clusters will shine brightly. Direct sow several weeks before final frost in average soil. Once established, sweet alyssum is drought tolerant and the flowers will keep coming until frost. Cut them back by half in the middle of summer for a fresh flush of foliage and flowers, or sow more seed in late summer for a fall bloom.
Hyacinth bean (Lablab purpureus):
Direct sow this vigorous vine at the feet of a sturdy structure it can climb. Any decent, well-draining soil in full sun will do and it will bloom continuously all season long. Spikes of fragrant pea-like blossoms come in rosy purple, pink and white. Once pollinated, these form ruby-purple seed pods that are edible if cooked before they ripen. Japanese beetles love their leaves, but the vigorous vines will regroup to form new foliage and carry on into autumn.
Hyacinth bean image credit: Dwight Sipler/CC BY 2.0
Snapdragon (Antirrhinum majus):
Start these seeds indoors several weeks before the final frost date and then plant them out in moist, rich soil and full sun once all threat of frost has passed. Pinch young plants to promote bushiness, and they will still grow one to three feet tall and bloom profusely until the frost knocks them down. Varieties come in countless colors, pastel or bright or even bicolor. If snapdragons languish in midsummer, cut them back hard and feed them for a second round of bloom.
Common zinnia (Zinnia elegans):
Most zinnias grow between one and three feet tall. They can bear single, semi-double or fully double blossoms of every color except black and blue. All make excellent cut flowers. You can create an extended sequence of flowering by direct sowing zinnia seed in two- to three-week intervals from mid-spring until summer. Be sure to thin these seedlings, though, to prevent overcrowding and the potential for midsummer mildews. Humusy, moist soil in full sun is best. Japanese beetles like these, so be vigilant.
Giant larkspur (Consolida ajacis):
Easily mistaken for perennial larkspur (Delphinium), this blue-, pink- or white-blooming beauty excels as a cool-weather annual. Sow seeds in loose, moderately rich, well-drained soil that never dries out. Best in full sun with some afternoon shade. An excellent cut flower, harvest regularly for arrangements. This will also prolong the bloom time. There is no need to stake these shorter cousins of delphinium, as they rarely reach four feet tall.
