10 Fast-Growing Seeds For Summer Flowers

Summer Flower Seed Packets — Photo: Antonis Achilleos; Styling: Buffy Hargett Miller

Hope isn't lost for those of us who spent the last weeks of winter indoors instead of prepping our garden for spring. Gather a few seed packets of these summer-blooming flowers and get started this weekend. All of these plants germinate, grow, and bloom quickly, so you can reap the rewards before the end of summer. Some even reseed, saving you the trouble of planting them again (after all, you know you might end up procrastinating next year). Try one or all of our favorite flowers to grow from seed and rest assured you'll have a beautiful summer garden.

01 of 10

Sunflowers

Botanical Name: Helianthus annuus
Sun Exposure: Full
Soil Type: Well-drained, loamy, loamy clay, sandy loam
Soil pH: Slightly acidic (6.0-6.8)

Annual sunflowers have sunny yellow or reddish blooms that can reach anywhere from 2 to 10 feet tall, depending on the variety. Plant seeds in rich, moist soil following a good rain after the last spring frost (for giant sunflowers, you'll want to plant them 2 feet apart). The seeds germinate in about 10 days, with some varieties blooming as early as 10 weeks after planting. The stalks may require staking as they grow tall and top-heavy. Cut sunflowers for seasonal arrangements or let the flower heads dry and collect the seeds.

02 of 10

Zinnias

Botanical Name: Zinnia spp.
Sun Exposure: Full
Soil Type: Well-drained, average garden soil
Soil pH: Acidic to neutral (5.5-7.5)

Lollygagging gardeners can wait until late spring or even early summer to sow the seeds of heat-loving zinnias. Zinnias come in a profusion of colors and sizes and will also attract butterflies and birds to your garden. Plant the seeds in moist garden soil after all danger of frost has passed. They germinate in as little as five days when soil temperatures are above 70°F, start blooming in about eight weeks, and continue flowering until the first frost in fall. Pinching and deadheading will encourage more blooms.

03 of 10

Spider Flower

Botanical Name: Cleome spp.
Sun Exposure: Full
Soil Type: Well-drained, average garden soil
Soil pH: Slightly acidic to neutral (6.0-7.0)

Spread quick-sprouting spider flower seeds in warm soil along the fence line of your garden so they'll have room to grow into towering, whiskery flowers. The seedlings appear in one to two weeks, followed by flowers in 70-80 days. Spider flower climbs upward over the course of the summer, producing a stalk that eventually reaches 4 or 5 feet (some new cultivars are more compact). Older varieties self-seed with abandon, saving you the trouble of planting more seeds next year.

04 of 10

Marigolds

Orange Marigold Flower — Hector Manuel Sanchez

Botanical Name: Tagetes spp.
Sun Exposure: Full
Soil Type: Well-drained
Soil pH: Slightly acidic to neutral (6.0-7.0)

Spicy-scented marigolds are practically a requirement in the summer garden, whether you plant them in containers, along a flower border, or as a companion plant to tomatoes. Sow them in well-drained soil, where they will sprout quickly in warm weather. The vivid, ruffled flowers should appear in about eight weeks. These tough, drought-tolerant plants will bloom all summer until the first frost. Pinch off spent blooms to encourage more flowering.

05 of 10

Nasturtiums

Botanical Name: Tropaelum majus
Sun Exposure: Full, partial
Soil Type: Well-drained, sandy, loamy
Soil pH: Slightly acidic to slightly alkaline (6.0-7.8)

Get moving on this classic flower—they prefer cooler temperatures and will wither in peak summer heat. Plant easy-to-grow nasturtiums in hanging baskets or flower boxes in sandy, well-drained soil. Coax the seeds into sprouting faster by soaking them in water overnight before planting. They will germinate in a week and bloom 8-12 weeks later. Give them afternoon shade in hot weather and do not fertilize them; you'll get fewer flowers in overly rich soil. Snip the flowers and use them as a peppery garnish on salads.

06 of 10

Cosmos

Botanical Name: Cosmos spp.
Sun Exposure: Full
Soil Type: Well-drained
Soil pH: Slightly acidic to slightly alkaline (6.5-7.5)

Colorful cosmos take 8-14 weeks to develop from seed to flower, attracting both birds and butterflies. This prolific self-seeder is also known as Mexican aster, so you won't be surprised to hear it handles dry, hot conditions with little complaint. Press or rake the seeds in well-drained, weed-free soil and water lightly until established. Then let the rain do all the work, sit back, and enjoy the show.

07 of 10

Morning Glory

Botanical Name: Ipomoea tricolor
Sun Exposure: Full
Soil Type: Well-drained but moist, loamy, sandy
Soil pH: Slightly acidic (6.0-6.8)

A native of tropical and subtropical regions, morning glories perform well in a hot Southern climate. Speed up the growth of their hard seeds by soaking them overnight or making a small cut in the coating before planting, and make sure to plant them in warm soil. The vines grow to 10 feet long very quickly, with each flower opening in the morning and dropping by nighttime. Some find morning glory a nuisance, as it reseeds easily and the seeds are toxic. This nostalgic flower shouldn't be planted around grazing animals or curious pets.

08 of 10

Blanket Flower

Botanical Name: Gaillardia pulchella
Sun Exposure: Full
Soil Type: Well-drained but moist, sandy
Soil pH: Neutral (6.8-7.2)

This native plant thrives in the heat and salt air of coastal areas. Give low-maintenance blanket flowers good drainage, and that's about all you'll have to do. Gaillardia takes about three months to bloom after sowing seeds. Scatter the seeds over well-drained, preferably sandy soil, press them into the surface, and moisten the soil. Once established, blanket flower needs little intervention or care.

09 of 10

Four O'Clock

Botanical Name: Mirabilis jalapa
Sun Exposure: Full, partial
Soil Type: Well-drained, organically rich
Soil pH: Slightly acidic to neutral (6.0-7.0)

Four o'clocks are so named because their small, cup-shaped flowers open towards the end of the day, attracting nectar-feeding moths as well as hummingbirds. The tender, shrubby foliage is perennial in USDA plant hardiness zones 9 and 10, and may sometimes reappear after a mild winter in other parts of the South. The seeds can take one to three weeks to sprout; soak them overnight to speed up germination, and you'll see blooms on this "Marvel of Peru" in 12 weeks.

10 of 10

Globe Amaranth

Botanical Name: Gomphrena globosa
Sun Exposure: Full
Soil Type: Well-drained, average garden soil
Soil pH: Slightly acidic to neutral (6.0-7.0)

Globe amaranth's pincushion flowers keep on coming no matter how hot or dry the weather is, making it a reliable performer in the Southern garden. Wait until the soil is at least 65°F before planting seeds (some gardeners say they have more success starting seeds indoors, and a heat mat will speed up the process). Be very generous in the amount of seeds you sow for more likelihood of success. In 12 weeks, you'll be admiring globe amaranth blooms in your garden.

Was this page helpful?

Thanks for your feedback!

Tell us why!