Many of summer’s best flowers are easily started from seed about 6-8 weeks before warm weather arrives. Seed-grown flowers save you money compared to buying plants. And our generous seed packs mean you can plant lots of flowers — for a beautiful yard, to attract pollinators, and to cut and bring inside. Not all flower varieties will bloom in the current year, though, so if you’re new to flower gardening, choose from the following varieties to ensure blooms just a few months from now.
Ageratum Tall Blue. This is the robust variety with cool blue flowers that are the perfect compliment to the hot colors of most other summer annuals. Start 8 weeks before the weather is usually warm and settled. Ageratum germinates best at 80°F, taking 8-10 days, or longer at lower temperatures. The seeds require light to germinate, so do not cover with soil mix. A light dusting of vermiculite on the seeds will keep in humidity, as will a plastic cover. Space plants 9-12 inches apart.
Basil, Cinnamon. Did you know that this aromatic basil is a favorite with cut flower growers? The plants grow quite tall, up to 3 feet, and the stems are strong. It can be cut and used in bouquets simply for the delicious-smelling foliage, or you can wait until it flowers for extra appeal. Start seeds six weeks before final frost. At 70°F, basil germinates in 5-10 days. Cover seeds lightly with soil mix and keep moist. Space plants 12 inches apart.
Calendula. Some people grow the 20-inch-tall plants as an edible, some as a medicinal. But it’s pretty enough that you can just let it bloom in the garden. Start seeds 8 weeks before frost-free date; germination takes 10 days at 70°F. Cover the seed, as it requires darkness to germinate. Space plants 6-12 inches apart. We have both single orange and mix colors.
Celosia. We have both plumed and crested varieties. Both are interesting accents in the garden and bouquets. Start seeds 8 weeks before warm weather. Germination will take 8-10 days on an 80-85°F heat mat. Cover seeds and keep moist. Space plants 9-12 inches apart.
Pictured: Zinnia, Ageratum Tall Blue, Gomphrena, Calendula.
Cosmos. Our open-pollinated seed is the tall kind in a mix of pinks, purples, and white. Germination takes 7-10 days at 70°F. Space plants 9-12 inches apart.
Gomphrena, a.k.a. Globe Amaranth. The cheerful little ball-shaped flowers are borne in profusion on branched plants. Start seed 8 weeks before last frost at 70°F; germination takes 10 days. Space plants 9-12 inches apart.
Marigold. Start seeds 6 weeks before last frost. Germinates in 5-7 days at 80°F. Space plants 9-18 inches apart.
Nasturtium. We have the bush type (Nano), which is good for growing in the ground, and the trailing type (Rampicante), which is good for a hanging basket or for growing up a trellis. Direct seed 2 weeks before last frost. Plants dislike transplanting so if you do start inside earlier, use a peat pot or other biodegradable container. Space plants 9-12 inches apart.
Scabiosa, a.k.a. Pincushion Flower. Tall, wiry stems make great cut flowers. Start seeds 6 weeks before last frost at 65-70°F. Space plants 12 inches apart.
Zinnia. We have a couple of fantastic open-pollinated mixes that will provide diverse colors and forms. Try the Cactus for big, fluffy flowers or the Dahlia for a more refined look. Those two get to 4 feet tall; we also have Thumbelina for short, mounded plants with small flowers. Start seeds 4 weeks before last frost. Germination is 5 days at 80°F. Space plants 12-18 inches apart.