Late summer may seem like the end of the growing season, but it’s actually a great time to plant flowers that will bloom into fall or establish themselves before winter. Whether you want bold blooms to refresh tired garden beds or prefer preparing for early spring color, planting in late summer gives your flowers a head start. To get the best results, you need to know the right flowers to choose, when to plant them, and how to adjust your timing based on your USDA hardiness zone.
Why Plant Flowers in Late Summer?
By late summer, many spring and early summer flowers have faded. Adding new flowers now helps keep your garden full and colorful into the fall. It’s also the perfect time to plant perennials that will root well before winter sets in. Late summer planting gives them time to grow strong roots, which means they’ll bloom earlier and more robustly next year. Additionally, many garden centers offer discounted plants in late summer, making this the perfect season to refresh your beds.
Annual Flowers to Plant in Late Summer
Marigolds
Marigolds are fast growers and can still thrive when planted in late summer. Choose smaller varieties like French marigolds if you’re closer to your first frost date. They’ll bloom well into fall and bring rich yellows and oranges to your garden.
Nasturtiums
These quick-growing annuals are perfect for planting in late summer. Nasturtiums love cooler nights and will bloom through fall. They also make great companion plants and edible flowers.
Calendula
Calendula, also known as pot marigold, is another great choice. It prefers cooler temperatures and will bloom from late summer into early winter in mild climates.
Zinnias
In warmer zones, zinnias planted in late summer will still have time to flower. These heat-loving annuals germinate and grow quickly. Choose dwarf varieties for containers or edges.
Perennials to Plant in Late Summer
Coneflowers (Echinacea)
Late summer is the perfect time to plant coneflowers. They’ll establish their root systems in the cooler fall months and bloom the following year. They thrive in full sun and attract pollinators.
Black-Eyed Susan (Rudbeckia)
These cheerful yellow flowers are tough and drought-tolerant. Planting them in late summer gives them a jump start for next year. They can also bloom in the first season if the weather stays warm long enough.
Shasta Daisies
Shasta daisies enjoy cooler weather and can be planted in late summer for fall root development. In zones with mild winters, they may even produce a few blooms before frost.
Coreopsis
This long-blooming perennial can still be planted in late summer. It establishes quickly and can add splashes of yellow, pink, or orange well into fall.
Sedum (Stonecrop)
Sedum is an excellent choice for late summer planting, especially varieties like ‘Autumn Joy.’ These succulent perennials bloom in late summer and fall and provide year-round structure.
Biennials to Plant in Late Summer
Biennials are plants that grow foliage the first year and bloom the second. Late summer is the right time to start these if you want blooms next spring or early summer.
Foxgloves
Foxgloves are classic cottage garden flowers that form leafy rosettes the first year. Planting them in late summer ensures beautiful tall blooms next year.
Hollyhocks
Hollyhocks also benefit from late summer planting. These towering beauties will grow foliage now and shoot up blooms the following year.
Sweet William
Sweet William is a fragrant biennial that blooms in clusters. When planted in late summer, it will overwinter and bloom early in spring.
Flower Bulbs to Plant in Late Summer
Some bulbs benefit from early fall planting, and late summer is a good time to get them in the ground before the soil cools.
Colchicum (Autumn Crocus)
Colchicum blooms in fall, just weeks after planting. Get them in the ground by late August and enjoy their purple or pink flowers before frost.
Cyclamen hederifolium
This hardy fall-blooming cyclamen adds delicate beauty beneath trees and in shaded areas. Plant in late summer for fall flowers and winter foliage.
Crocus and Daffodil
While most spring-flowering bulbs are planted in mid to late fall, warmer zones (8-10) can begin planting them in late summer to ensure enough chilling hours.
When to Plant by Zone
Timing is everything when planting flowers in late summer. You need to consider how much time remains before the first frost and how long each plant needs to mature or establish roots.
Zones 3-4
In these colder zones, the growing season ends early. Late summer planting should be done by mid-August. Choose quick-growing annuals like marigolds and nasturtiums or hardy perennials like coneflowers and sedum. Biennials like foxglove can be started from seed now and overwintered under mulch.
Zones 5-6
You have until late August to early September to plant in these zones. Many perennials will do well when planted now, especially black-eyed Susan, Shasta daisy, and coreopsis. Annuals can still be sown for short-term color. Fall bulbs like colchicum should go in by the end of August.
Zones 7-8
In these warmer zones, you can plant well into September. Zinnias and calendula will bloom quickly, and perennials will establish easily. You can also start sowing sweet William and other biennials. Now is a good time to begin fall bulb planting.
Zones 9-10
These zones enjoy extended warm weather. Late summer planting continues into October. Plant heat-tolerant annuals like zinnias or tropical-looking perennials. Daffodils and crocus bulbs should go in by late September to ensure enough cool hours. You can also begin cool-season annuals like pansies and violas in containers.
How to Prepare Your Garden for Late Summer Planting
Before planting, make sure your garden beds are refreshed. Summer flowers may have used up much of the nutrients in the soil, so start by removing spent plants and weeds. Add compost or a slow-release balanced fertilizer to enrich the soil. If you’re planting in containers, replace old potting mix or refresh it with new compost.
Water new plants thoroughly and mulch to retain moisture. Even though days are getting shorter, late summer sun can still be intense. Shade new transplants for a few days if needed. Continue to water regularly, especially during hot spells, to help roots establish.
Extra Tips for Success
– Deadhead summer flowers: This can make room for new growth and give your late plantings more room to shine.
– Add mulch: It will help protect new roots as temperatures begin to drop.
– Use containers: If your soil is hard or depleted, planting in containers filled with fresh mix is a quick solution.
– Watch the forecast: If an early frost is expected, cover tender young plants or bring containers indoors at night.
Conclusion
Late summer doesn’t mean your flower garden has to wind down. With the right selection and proper planting times by zone, you can enjoy blooms into the fall or prepare for a vibrant spring. Whether you choose annuals like nasturtiums and zinnias, perennials like black-eyed Susan and coneflowers, or biennials like foxglove, planting in late summer sets your garden up for long-term success. As always, tailor your planting to your zone for the best results—and keep the color going right up to frost.
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