20 Perennial Flowers that Bloom all Summer

The best way to achieve all summer color in your flower beds is to choose perennials with the longest possible bloom time. I have put together a list of the most eye catching flowers that bloom for 8-12 weeks. Since they are perennials, they will come back to life every year to fill your garden with low maintenance beauty.

Keep in mind that only select varieties of these plant species may flower for 8-12 weeks. Carefully ready read the description for any variety you are purchasing. Growing zone, hours of sunlight per day and watering frequency also impact how long a plant will continue to bloom throughout the summer season.

Off With Their Heads!

The queen of hearts must have been a great gardener, because she knew the secret to a colorful garden! Deadhead flowers to prolong their bloom time. To do this, cut the stem with pruning scissors just below the flower head.

Deadheading stimulates new growth so the plant will continue to produce new blooms. When a plant keeps it’s spent flower heads, it puts energy into seed production instead of blooming. Deadheading can also allow bulb flowers to put energy into root growth instead of their seeds.

Which flowers need deadheading? Rudbeckia, Coneflower, Agastache, Daisies, Lavender, Peonies, Roses and most annuals benefit from deadheading. If a plant is labeled as “continuous bloom” or “self-cleaning”, it does not need to be deadheaded.

Perennials that Bloom 8-12 Weeks


1. Agastache (Hyssop)

Height: 2-6’

Spacing: 20-36”


2. Bellflower

Height: 12-30”

Spacing: 15-24”

Bleeding Heart

3. Bleeding Heart

Height: 9-36”

Spacing: 12-36”


4. Clematis

Height: 6-12’ climbing vine

Spacing: 24-36”


5. Coneflower

Height: 2-4’

Spacing: 18-24”


6. Coreopsis (Tickseed)

Height: 6-24”

Spacing: 18-24”


7. Corydalis

Height: 12-36”

Spacing: 15-36”


8. Daylily

Height: 1-8’

Spacing: 12-36”


9. Dianthus

Height: 6-36”

Spacing: 6-24”


10. Daisy

Height: 12-36”

Spacing: 12-24”


11. Gaura

Height: 1-8’

Spacing: 12-24”


12. Geranium (Cranesbill)

Height: 12-24”

Spacing: 18-36”


13. Honeysuckle Vine

Height: 7-30’ climbing vine

Spacing: 2-5’


14. Milkweed (Swamp)

Height: 1-8’

Spacing: 12-36”


15. Pincushion (Scabiosa)

Height: 12-24”

Spacing: 15-18”


16. Rudbeckia ( Black-Eyed Susan)

Height: 24-36”

Spacing: 18-24”

Russian Sage

17. Russian Sage

Height: 3-8’

Spacing: 24-36”

Ornamental Strawberry

18. Strawberry, Ornamental (Fragaria)

Height: 4-6”

Spacing: 15-18” Ground cover that spreads via runners


19. Veronica

Height: 6-36”

Spacing: 8-24”


20. Viola

Height: 6-12”

Spacing: 4-12”

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20 Perennial Flowers that Bloom all Summer

4 thoughts on “20 Perennial Flowers that Bloom all Summer”

  1. I am currently trying to create a cottage garden in my back garden in the north of Scotland. I loved you post and being new to gardening I greatly valued your shared knowledge. I am currently walking around with a shopping list of flowers and plants so when I stumbled across your post it helped me alot.

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