Running a little behind on planting? No worries—these fast-growing flowers are perfect for catching up without missing out on the season.
I’ve planted some of these well past their “ideal” time and still got beautiful results. With a little care and a few easy tricks, they’ll be blooming before you know it.
Let’s get those late-start gardens bursting with color in no time.
1. Sunflowers
Nothing says summer quite like these cheerful giants reaching for the sky. From seed to bloom in just 8-10 weeks, they’re perfect for impatient gardeners who want dramatic results fast.
Plant them in a sunny spot with well-draining soil, water deeply but infrequently, and watch them grow several inches daily. For best results, space them properly—about 6 inches apart—so they don’t compete for nutrients.
2. Nasturtiums
Ready to bloom just 4-6 weeks after planting, these vibrant flowers bring a punch of orange, red, and yellow to any garden space. They actually prefer poor soil, making them perfect for gardeners with less-than-ideal growing conditions.
Simply sow seeds directly where you want them to grow and barely cover with soil. Their edible flowers and leaves add a peppery zip to salads, making them both beautiful and functional in your late-starting garden.
3. Marigolds
From seed to flower in just 8 weeks, these hardy bloomers are practically foolproof for beginners. Their bright orange and yellow flowers keep going strong until frost, providing months of color even with a late start.
As a bonus, they naturally repel many garden pests with their distinctive scent. Plant them around your vegetable garden for natural protection. Water at the base rather than overhead to prevent powdery mildew on their dense blooms.
4. Zinnias
Bursting with color just 6-8 weeks after planting, zinnias are the speedsters of the flower world. Available in practically every color except blue, they’ll keep producing new blooms all season if you deadhead regularly.
Direct sow these heat-lovers after all danger of frost has passed. Their sturdy stems make them perfect for cutting gardens, and pollinators absolutely adore them. For continuous blooms, plant new seeds every few weeks through mid-summer.
5. Cosmos
Graceful and airy, cosmos sprint from seed to bloom in about 7 weeks. Their delicate, daisy-like flowers dance above ferny foliage, creating movement and lightness in any garden space.
These drought-tolerant beauties actually bloom better in poor soil, so skip the fertilizer. Simply scatter seeds, lightly cover with soil, and water occasionally. Their self-seeding nature means they’ll return year after year, saving you work in future seasons.
6. Morning Glories
Transforming from seed to spectacular in just 10 weeks, these vigorous climbers create vertical interest in record time. Their trumpet-shaped blooms unfurl each morning in shades of blue, purple, pink, and white.
Soak seeds overnight before planting to speed germination. Provide a trellis or fence for support as they can grow 10 feet in a single season. Morning glories thrive with minimal care—just regular water and full sun keep them happy.
7. Sweet Alyssum
From tiny seeds to fragrant carpet in just 6 weeks, sweet alyssum creates a low-growing blanket of tiny blooms. The honey-scented flowers attract beneficial insects while softening garden edges and spilling beautifully from containers.
Simply scatter seeds and barely cover with soil—they need light to germinate. For continuous blooms in hot climates, give them afternoon shade and trim back by half if they become leggy during summer heat.
8. Calendula
Often called pot marigold, calendula races from seed to bloom in just 6-8 weeks. The edible, daisy-like flowers in golden yellows and oranges have been used for centuries in cooking and herbal remedies.
Direct sow in well-draining soil and keep evenly moist until established. These cool-weather lovers will continue blooming through fall and even mild winters in some regions. Harvest flowers regularly to encourage more blooms and use in salads or homemade skin care.
9. California Poppies
Going from seed to vibrant bloom in just 60 days, these golden beauties are perfect for gardeners who missed early spring planting. Their silky, cup-shaped flowers close at night and on cloudy days, then open wide in sunshine.
Sow directly where you want them to grow—they hate transplanting. Once established, they’re extremely drought-tolerant and will self-seed readily. For best results, choose a spot with full sun and well-draining soil.
10. Bachelor’s Buttons
Ready to show off their vivid blue blooms in just 7-8 weeks from sowing, these charming flowers are as easy as they are beautiful. Also known as cornflowers, they attract butterflies and make excellent cut flowers that hold their color when dried.
Scatter seeds directly in the garden after danger of frost has passed. They prefer cool weather but tolerate summer heat in most regions. Deadhead regularly to extend the blooming season and prevent excessive self-seeding.
11. Four O’Clocks
Named for their habit of opening in late afternoon, these fragrant flowers go from seed to bloom in about 8 weeks. Their trumpet-shaped flowers in pink, yellow, white, and magenta release a sweet scent that attracts hummingbirds and moths.
Plant in full sun to partial shade after all danger of frost has passed. Their tuberous roots store energy, making them surprisingly drought-tolerant once established. In warmer zones, they’ll return year after year from their self-sown seeds.
12. Petunias
While many gardeners buy petunia seedlings, you can grow these colorful favorites from seed in just 8 weeks. Modern varieties offer improved heat tolerance and rain resistance, keeping your late-started garden gorgeous through summer.
Start seeds indoors for faster results or buy young plants for instant impact. Pinch back leggy growth to encourage bushiness and deadhead regularly. Feed every two weeks with liquid fertilizer to keep the flower show going strong until frost.
13. Phlox
Annual phlox varieties like Drummond phlox burst into bloom just 6-8 weeks after planting. Their star-shaped flowers create masses of color in shades of pink, red, purple, and white.
Sow seeds directly in the garden after frost danger passes. For best performance, provide rich, well-draining soil and regular water. Their low-growing habit makes them perfect for borders, rock gardens, or spilling from containers.
14. Portulaca
Also called moss rose, these heat-loving succulents bloom just 8 weeks after planting. Their cactus-like flowers in vibrant pinks, oranges, yellows, and whites open in sunshine and close on cloudy days.
Plant in poor, well-draining soil and full sun for best results. Their drought tolerance makes them perfect for hot, dry spots where other flowers struggle. The low-growing, spreading habit works beautifully in rock gardens or as living mulch around taller plants.
15. Sweet Peas
Filling the garden with their heavenly fragrance just 10 weeks after planting, sweet peas are worth the slightly longer wait. Their ruffled blooms in pastels and bright colors make gorgeous bouquets that perfume your entire home.
Soak seeds overnight before planting to speed germination. Provide a trellis or support for their climbing tendrils. In warmer regions, look for heat-tolerant varieties that will continue blooming even as temperatures rise.
16. Nigella
Also called love-in-a-mist, these charming flowers go from seed to bloom in just 8-10 weeks. Their delicate blue, pink, or white star-shaped flowers are surrounded by feathery foliage that creates a misty effect in the garden.
Sow directly where you want them to grow—they dislike transplanting. The unusual seed pods that follow the flowers are prized for dried arrangements. Allow some plants to set seed, and they’ll self-sow for years of effortless blooms.
17. Celosia
Reaching blooming size in just 8 weeks, celosia brings tropical flair with its unique flower forms. Choose from plume types with feathery spires or cristata varieties with fascinating brain-like crests in vibrant reds, oranges, and yellows.
Plant in rich, well-draining soil after all danger of frost has passed. Their heat and drought tolerance makes them perfect for hot summer gardens. The dramatic blooms dry beautifully for long-lasting arrangements that maintain their vivid colors.
18. Annual Salvia
Racing from seed to bloom in just 8 weeks, annual salvias create spires of color that attract hummingbirds and butterflies. Most common in reds and blues, newer varieties offer purples, pinks, and bicolors for the late-starting garden.
Plant in full sun for best flowering and provide well-draining soil. Their drought tolerance once established makes them low-maintenance choices for busy gardeners. Deadhead regularly to encourage continuous blooming through fall.
19. Impatiens
Ready to bloom in just 8-10 weeks from seed, impatiens bring reliable color to shady spots where few other flowers thrive. Their continuous flowers in white, pink, red, orange, and purple need no deadheading to keep producing.
Choose disease-resistant varieties like New Guinea impatiens for best results. Keep soil consistently moist but not soggy, and feed regularly with diluted liquid fertilizer. Their compact growth habit makes them perfect for containers and woodland garden edges.
20. Lobelia
Creating cascades of tiny blooms just 8 weeks after planting, lobelia adds delicate beauty to any garden. Most popular in stunning blues, they also come in white, pink, and purple varieties that spill beautifully from containers.
Start seeds indoors for faster results or purchase young plants. They prefer cooler temperatures, so provide afternoon shade in hot climates. Keep soil consistently moist, as they’re not drought-tolerant. Trim back by half if they become leggy in midsummer heat.