Are you in need of some inspiration for your next garden project and looking to add late-flowering herbaceous plants that will carry your display well into early autumn? As summer begins to wind down, September offers a second wave of vibrant colour, texture, and pollinator activity. Many perennials reach their peak during this time, providing bold blooms and architectural interest just when other parts of the garden may be fading. From the sculptural heads of Sedum to the graceful sway of Anemones, these reliable performers are perfect for filling seasonal gaps and extending the beauty of your borders.
Achilleas are a great addition to a mixed border or cottage garden in full sun – partial shade with flat-topped flowers that bloom from June – September with many cultivars and colours to choose from ranging from yellow to white and pink.
Flowers: June-September (depending on variety)
Position: Full sun – partial shade (depending on variety)
Height: Up to 1m (depending on variety)
Soil: Moist, well-drained soil
Pot size: 2L, 3L, 5L (depending on variety and subject to availability)
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Anemone (Japanese Windflower) is a graceful perennial that blooms from late summer into autumn, adding soft colour and movement to borders. With tall, airy stems and delicate pink or white flowers, it’s ideal for partial shade and pairs beautifully with ferns and grasses. Low-maintenance and long-flowering, it’s a standout in late-season gardens.
Flowers: August – October (depending on variety)
Position: Full sun – partial shade
Height: Up to 1.2m (depending on variety)
Soil: Moist, fertile, humus-rich soil
Pot size: 2L, 3L (depending on variety and subject to availability)
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Alchemilla mollis (Lady’s Mantle) is a hardy perennial known for its soft, scalloped leaves that catch dewdrops and airy sprays of yellow-green flowers in early summer. It thrives in sun or partial shade, spreads gently, and makes an excellent groundcover or edging plant. Perfect for softening paths and mixing with cottage garden perennials.
Flowers: June-September (depending on variety)
Position: Full sun – partial shade
Height: Up to 0.6m
Soil: Humus-rich soil
Pot size: 2L, 3L, 5L
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Alstroemeria (Peruvian Lily) is a long-flowering perennial prized for its vibrant, lily-like blooms that appear from late spring through autumn. Available in a wide range of colours—pink, orange, red, yellow, and white—its flowers are perfect for cutting and last well in vases. Alstroemeria thrives in sun or partial shade, prefers well-drained soil, and offers a bold splash of colour in borders or containers.
Flowers: June-September (depending on variety)
Position: Full sun – partial shade
Height: Up to 0.9m (depending on the variety)
Soil: Fertile, moist, well-drained soil
Pot size: 3L
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Agastache (also known as Hyssop or Hummingbird Mint) is a fragrant, upright perennial prized for its spikes of tubular flowers in shades of purple, pink, orange, or blue from mid-summer to autumn. Loved by bees, butterflies, and hummingbirds, it thrives in full sun and well-drained soil, tolerating heat and drought. Its aromatic foliage and long bloom time make it perfect for pollinator gardens, prairie-style borders, and dry, sunny spots.
Flowers: July – October (depending on variety)
Position: Full sun
Height: Up to 1m (depending on the variety)
Soil: Fertile, well-drained soil
Pot size: 2L. 3L
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Agapanthus (African Lily) is a striking perennial known for its tall stems topped with globe-like clusters of blue, violet, or white flowers in mid to late summer. Its strappy green leaves form neat clumps, and it thrives in sunny, well-drained spots, making it ideal for borders or containers. Drought-tolerant and elegant, Agapanthus adds bold, architectural interest to the garden.
Flowers: July – September (depending on the variety)
Position: Full sun
Height: Up to 1m (depending on variety)
Soil: Fertile, moist, well-drained soil
Pot size: 2L, 3L, 5L (depending on variety and subject to availability)
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Aster (also known as Michaelmas Daisy) is a late-blooming perennial that brings a burst of colour from late summer into autumn. With daisy-like flowers in shades of purple, pink, blue, or white, it’s a favorite for pollinators, especially bees and butterflies. Asters thrive in full sun to partial shade and work beautifully in borders, wildlife gardens, and mixed plantings.
Flowers: August – October (depends on the variety)
Position: Full sun
Height: Up to 0.9m (depending on variety)
Soil: Well-drained, moderately fertile soil
Pot size: 2L, 3L
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Campanula (Bellflower) is a versatile perennial known for its bell-shaped flowers in shades of blue, purple, or white, blooming from late spring through summer. With varieties ranging from low-growing groundcovers to upright border plants, Campanula thrives in sun or partial shade and prefers well-drained soil. It adds a soft, cottage-garden feel and is great for edging, rock gardens, or mixed borders.
Flowers: July – September (depends on the variety)
Position: Full sun – partial shade
Height: Up to 0.3m (depending on variety)
Soil: Moist, well-drained, soil
Pot size: 2L
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Coreopsis (Tickseed) is a cheerful, long-blooming perennial known for its bright, daisy-like flowers in shades of yellow, gold, orange, or pink. Blooming from early summer to autumn, it thrives in full sun and well-drained soil, and is loved by pollinators. Coreopsis is drought-tolerant, easy to grow, and perfect for borders, wildlife gardens, and sunny containers.
Flowers: June – September (depends on the variety)
Position: Full sun -partial shade
Height: Up to 0.5m (depending on variety)
Soil: Fertile, well-drained soil
Pot size: 3L
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Crocosmia (also known as Montbretia) is a vibrant, clump-forming perennial that produces arching stems of fiery, funnel-shaped flowers in shades of red, orange, or yellow from mid to late summer. Its sword-like foliage adds structure and movement, and the blooms are magnets for bees, butterflies, and hummingbirds. Thriving in full sun to partial shade and well-drained soil, Crocosmia is perfect for adding bold colour to borders and late-summer displays.
Flowers: August – September
Position: Full sun -partial shade
Height: Up to 1.2m (depending on variety)
Soil:Moderately fertile, humus-rich, well-drained soil
Pot size: 3L, 5L
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Dahlia is a show-stopping perennial grown for its striking, colourful blooms that range from small, delicate singles to large, dinner-plate-sized flowers. Blooming from mid-summer until the first frost, dahlias come in nearly every colour except true blue. They thrive in full sun and rich, well-drained soil, and are perfect for cut flower gardens, borders, and statement containers. Though technically tender perennials, dahlias are often lifted and stored over winter in colder climates.
Flowers: June – September (depends on the variety)
Position: Full sun -partial shade
Height: Up to 0.5m (depending on variety)
Soil: Fertile, well-drained soil
Pot size: 3L
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Echinacea (Coneflower) is a bold, upright perennial known for its large, daisy-like flowers with prominent central cones, blooming from mid-summer into autumn. Most commonly found in shades of purple, pink, white, and orange, Echinacea is a magnet for bees, butterflies, and birds. It thrives in full sun and well-drained soil, is drought-tolerant, and adds long-lasting color and structure to prairie-style plantings, wildlife gardens, and sunny borders.
Flowers: July – September
Position: Full sun
Height: Up to 1m (depending on variety)
Soil: Most soils, except very dry or boggy
Pot size: 2L, 3L
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Erigeron (commonly known as Fleabane) is a charming, low-growing perennial that produces masses of small, daisy-like flowers in shades of white, pink, or lilac with yellow centers. Blooming from late spring through autumn, it thrives in full sun to partial shade and prefers well-drained soil. Erigeron is perfect for cottage gardens, walls, gravel paths, and edging, where it self-seeds gently to form natural-looking drifts.
Flowers: May – October (depending on variety)
Position: Full sun
Height: Up to 0.5m (depending on variety)
Soil: Fertile, well-drained soil
Pot size: 2L
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Geranium (Hardy Geranium or Cranesbill) is a reliable, low-maintenance perennial valued for its mounded foliage and long-lasting, saucer-shaped flowers in shades of pink, blue, purple, or white. Blooming from late spring through summer—and some varieties into autumn—it thrives in sun or partial shade and well-drained soil. Geraniums are excellent for groundcover, edging, or weaving through borders, and many varieties are deer-resistant and pollinator-friendly.
Flowers: June – October (depending on variety)
Position: Full sun – partial shade
Height: Up to 0.6m (depending on variety)
Soil: Fertile, well-drained soil
Pot size: 2L
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Leucanthemum (commonly known as the Shasta Daisy) is a classic, long-flowering perennial loved for its bold, white, daisy-like flowers with yellow centers, blooming from early summer into autumn. It thrives in full sun and well-drained soil, adding a fresh, cheerful look to borders, cottage gardens, and pollinator-friendly plantings. Compact, upright, and easy to grow, Leucanthemum pairs beautifully with grasses and late-summer perennials.
Flowers: June – September (depending on variety)
Position: Full sun – partial shade
Height: Up to 1m (depending on variety)
Soil: Moderately fertile, moist but well-drained soil
Pot size: 2L, 3L
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Liatris (commonly known as Blazing Star or Gayfeather) is a striking, upright perennial valued for its tall spikes of fluffy, purple or white flowers that bloom top to bottom from mid to late summer. Its grassy, clump-forming foliage stays neat, and the blooms are highly attractive to bees, butterflies, and other pollinators. Liatris thrives in full sun and well-drained soil, making it perfect for prairie-style borders, wildlife gardens, and sunny beds. It’s also drought-tolerant and excellent for cut flowers.
Flowers: August – September (depending on variety)
Position: Full sun
Height: Up to 1m (depending on variety)
Soil: Moderately-fertile, reliably moist soil
Pot size: 2L, 3L
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Nepeta (commonly known as Catmint) is a hardy, aromatic perennial known for its soft, grey-green foliage and clouds of small, lavender-blue flowers that bloom from late spring through summer, often into autumn. It thrives in full sun and well-drained soil, is drought-tolerant, and attracts bees and pollinators. With its relaxed, billowy habit, Nepeta is perfect for softening path edges, filling gaps in borders, or pairing with roses and grasses.
Flowers: June – September (depending on variety)
Position: Full sun- partial shade
Height: Up to 0.9m (depending on variety)
Soil: Moist, well-drained soil
Pot size: 2l, 3L, 5L (depending on variety and subject to availability).
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Penstemon (commonly known as Beardtongue) is a long-flowering perennial admired for its tall spires of tubular flowers in shades of pink, purple, red, white, or blue, blooming from early summer into autumn. Its elegant, upright form and nectar-rich blooms make it a favourite with bees and hummingbirds. Penstemon prefers full sun and well-drained soil, and works beautifully in mixed borders, cottage gardens, and pollinator-friendly plantings. Deadheading encourages a longer bloom period.
Flowers: July – October
Position: Full sun- partial shade
Height: Up to 1m (depending on variety)
Soil: Fertile, moist, well-drained soil
Pot size: 2l, 3L (depending on variety and subject to availability).
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Persicaria (commonly known as Knotweed or Bistort) is a bold, long-flowering perennial known for its dense spikes of small flowers in shades of red, pink, or white, blooming from mid-summer into autumn. It thrives in sun or partial shade and prefers moist, well-drained soil, making it ideal for naturalistic borders, damp spots, or prairie-style plantings. With its spreading habit and extended bloom time, Persicaria adds texture, movement, and late-season colour to the garden—and is loved by pollinators too
Flowers: June – October (depending on variety)
Position: Full sun- partial shade
Height: Up to 1m (depending on variety)
Soil: Any moist soil
Pot size: 2l (depending on variety and subject to availability)
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Perovskia (commonly known as Russian Sage) is a striking, aromatic perennial valued for its silvery-grey foliage and airy spikes of lavender-blue flowers, blooming from mid-summer into autumn. It thrives in full sun and well-drained soil, and is both drought-tolerant and deer-resistant. Perovskia adds a soft, hazy texture to borders and pairs beautifully with grasses, echinacea, and rudbeckia in prairie-style or Mediterranean plantings. It’s also a magnet for bees and butterflies.
Flowers: August – September (depending on variety)
Position: Full sun
Height: Up to 1.2m (depending on variety)
Soil:Well-drained, poor to moderately fertile
Pot size: 2l, 5L (depending on variety and subject to availability)
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Rudbeckia (commonly known as Black-eyed Susan) is a bold, late-summer perennial known for its bright yellow or gold daisy-like flowers with distinctive dark central cones. Blooming from mid-summer into autumn, it thrives in full sun and well-drained soil, and is loved by bees, butterflies, and birds. Rudbeckia adds vibrant colour and structure to borders, prairie-style plantings, and pollinator gardens, and pairs well with grasses and other late-season perennials.
Flowers: August – October (depending on variety)
Position: Full sun
Height: Up to 0.8m (depending on variety)
Soil: Moderately fertile, preferably heavy but well-drained soil
Pot size: 2l, 3L (depending on variety and subject to availability)
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Salvia (commonly known as Sage) is a vibrant, long-flowering perennial known for its spikes of tubular flowers in shades of blue, purple, pink, or red, blooming from late spring through summer, often into autumn. It thrives in full sun and well-drained soil, is drought-tolerant, and highly attractive to bees, butterflies, and hummingbirds. With aromatic foliage and a tidy habit, Salvia is perfect for borders, pollinator gardens, and Mediterranean-style plantings.
Flowers: June – October (depending on variety)
Position: Full sun
Height: Up to 1.2m (depending on variety)
Soil: Moderately fertile, moist but well-drained soil
Pot size: 2l, 3L,5L (depending on variety and subject to availability)
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Sanguisorba (commonly known as Burnet) is a graceful, clump-forming perennial valued for its tall, slender stems topped with bottlebrush-like flower heads in shades of crimson, pink, or white, blooming from mid to late summer into autumn. It thrives in full sun to partial shade and prefers moist, well-drained soil. With its airy form and soft movement, Sanguisorba is ideal for naturalistic, prairie-style, or cottage garden plantings, and is a favourite of pollinators.
Flowers: June – September (depending on variety)
Position: Full sun – partial shade
Height: Up to 0.6m (depending on variety)
Soil: Poor-to-average, moist, well-drained soil
Pot size: 2l, 3L (depending on variety and subject to availability)
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Scabiosa (commonly known as Pincushion Flower) is a charming perennial known for its dainty, pincushion-like blooms in shades of blue, lavender, pink, or white, flowering from late spring through to autumn. Loved by bees and butterflies, it thrives in full sun and well-drained soil, and makes an excellent addition to cottage gardens, borders, and pollinator-friendly plantings. Its compact habit and long bloom time also make it ideal for containers and cut flower gardens.
Flowers: June – September (depending on variety)
Position: Full sun
Height: Up to 0.5m (depending on variety)
Soil: Moderately fertile, well-drained, neutral to slightly alkaline soil
Pot size: 2l, 3L (depending on variety and subject to availability)
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Sedum (commonly known as Stonecrop) is a hardy, drought-tolerant perennial prized for its fleshy, succulent leaves and flat-topped flower heads that bloom from late summer into autumn. Flowers come in shades of pink, red, or white, and are highly attractive to bees and butterflies. Sedum thrives in full sun and well-drained soil, making it ideal for borders, gravel gardens, and containers. Its upright varieties add structure and seasonal colour, while low-growing types work well as groundcover.
Flowers: August – November (depending on variety)
Position: Full sun
Height: Up to 0.6m (depending on variety)
Soil: Moderately fertile, well-drained, neutral to slightly alkaline soil
Pot size: 2l, 3L, 5L (depending on variety and subject to availability)
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Verbena (especially Verbena bonariensis) is a tall, airy perennial known for its clusters of small, purple flowers held on slender, upright stems that bloom from summer into autumn. It thrives in full sun and well-drained soil, and is a magnet for bees, butterflies, and other pollinators. With its see-through form, Verbena adds height without blocking views, making it ideal for naturalistic borders, wildlife gardens, and contemporary plantings. It often self-seeds and returns reliably year after year.
Flowers: July – September
Position: Full sun
Height: Up to 2m (depending on variety)
Soil: Moderately fertile, moist but well-drained soil
Pot size: 2L, 3L (depending on variety and subject to availability)
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Whether you’re refreshing a tired border or planning a new design, these late-summer herbaceous perennials and shrubs are available now at Johnsons. Visit us in-store or get in touch to check current stock and expert recommendations tailored to your space.
Posted 12th Aug 2:20pm
