Perennials That Bloom All Summer

Updated September 2026 · Garden Advice Guide

The perennials that bloom all summer are a short list, and they share one thing: each flowers for 10 weeks or longer, either nonstop or in two flushes with a short gap you can control. Geranium 'Rozanne', catmint 'Walker's Low', threadleaf coreopsis, blanket flower, reblooming daylilies like 'Stella de Oro', Russian sage, whirling butterflies and autumn sage are the backbone. Most of them only reach that bloom length if you do the right thing at the right time, which is a shear, a deadhead, or a hard cut back, and doing the wrong one can cost you the second flush entirely.

This page groups the long bloomers into zone bands, gives the realistic weeks of bloom for each, and explains the rebloom method that gets you there.

Start with your zone: run your ZIP through our free growing zone lookup, then read your band and every colder band above it.

Updated September 2026

What counts as blooming all summer

Most perennials flower for two to four weeks. A peony gives you ten glorious days. The plants here are different because they keep producing new flower buds long after the first ones open, and they do it in one of three ways:

The weeks of bloom in the tables below assume you do the job listed. Skip it, and a 16 week catmint becomes a 5 week catmint.

We count bloom weeks from first real color to the point where the plant is no longer showing enough flowers to register from across the yard. Numbers shift with climate: long bloomers run longer in zones with mild summers and a late first frost, and shorter where July heat stalls them. Check your first frost with our frost date lookup, since that sets the end of the season for every plant here.

Perennials that bloom all summer in zones 2 to 4

The cold band has fewer choices, but the plants here are tough and long lived. Zone 2 in particular has almost no perennials that are both rated for its winters and this long blooming. Common yarrow and the hardiest daylilies are the usual survivors, especially under a dependable snow cover, and everything else below is best treated as a zone 3 plant.

Catmint is the best value here. 'Walker's Low' gives you lavender blue from late May into June, looks tired by early July, and comes back into full bloom within about four weeks of a hard shear. In a cool summer it keeps going until frost.

Reblooming daylilies need feeding more than most people realize. A rebloomer produces new scapes all season only if it has the energy to do it. Water deeply in dry spells and give a light feeding after the first wave. Clumps crowded for five or more years rebloom poorly and should be divided in spring.

Blanket flower lives longer when you stop it early. Gaillardia is naturally short lived, often two or three years, and it flowers itself to death. Cutting the plant back hard in late August, giving up the last few weeks of bloom, sends it into winter with more energy and a better chance of returning. It also rots in heavy, wet soil, which kills more blanket flowers than cold.

Perennials that bloom all summer in zones 5 and 6

Everything in the colder band grows here, plus a second tier that opens up once winter lows stay above about -20°F.

'Rozanne' is the longest bloomer most gardens can grow. Blue flowers with a white eye start in June and keep coming until frost, and because it sets almost no seed, it needs no deadheading. Its one weakness is sprawl. By mid July a mature plant can spread 3 feet and open in the middle. Cut the whole plant back by about half, water it in, and it regrows into a tidy mound that flowers into October.

Russian sage needs the opposite approach. It blooms on the current year's stems, so the main cut is in spring, when new growth shows at the base: take the old stems down to about 12 inches. Summer shearing costs you flowers. If it flops in rich soil, give it leaner, drier ground rather than cutting it in June.

Pincushion flower is the underused one. 'Butterfly Blue' covers the front of a sunny bed with lavender blue flowers from May to October, but only if every spent flower stem is cut off at its base. Seedheads left on the plant slow it to a trickle within weeks.

Corydalis is the shade answer. Almost every long bloomer on this page wants sun. Yellow corydalis flowers for four months in part shade and seeds itself into cracks in walls and paths.

Perennials that bloom all summer in zones 7 to 9

In warm zones the question flips. Cold is no longer the limit; summer heat and humid nights are. Several northern long bloomers fade here, and a set of southern perennials takes over that bloom far longer than anything that grows in zone 4.

Heat changes the northern plants. Catmint and 'Rozanne' both grow in zones 7 and 8, but in a hot, humid July they often stall or melt out in the center. Shear harder and earlier, give them afternoon shade, and expect a stronger fall flush once nights cool. In zone 9 most gardeners get better results from autumn sage and whirling butterflies.

Autumn sage is the longest bloomer on the page. In zones 8 and 9 it flowers in waves from spring to late fall on a woody, shrubby base. Shear it by about a third after each big flush and it pushes out new flowering tips within a few weeks. Leave the woody framework; cut into green growth, not bare old stems.

Reblooming daylilies still work here, though their summer waves are shorter in extreme heat. 'Stella de Oro' is grown across the South and reblooms well with water through the hottest weeks.

The three rebloom techniques

Three cuts do almost all of the work on long bloomers. They are different jobs, and using the wrong one on the wrong plant is the most common reason a "long blooming" perennial flowers for three weeks.

Shearing

What it is: cutting the whole plant back by a third to a half at once, flowers, stems and leaves together, with hedge shears or a sharp pair of scissors.

When: as soon as the first flush is about two thirds faded and the plant starts to look gray or floppy. Don't wait for every flower to finish.

Best for: catmint, threadleaf coreopsis, 'Rozanne' in midsummer, autumn sage, whirling butterflies, perennial lantana.

What to expect: a green, flowerless mound for two to three weeks, then a second flush that lasts nearly as long as the first. Water deeply right after shearing, because new growth in July heat needs moisture to come back strong.

Deadheading

What it is: removing individual spent flowers before they form seed, cutting down to the next bud, side shoot or pair of leaves.

When: weekly through the season. A few minutes on a warm evening covers a whole bed.

Best for: blanket flower, coneflower, shasta daisy, pincushion flower, yarrow, garden phlox, reblooming daylilies.

How for daylilies: each flower lasts one day. Snap off the spent blossoms so they don't form seed pods, and once every bud on a scape has opened, cut the whole scape off at its base. That tells the plant to put its energy into the next set of scapes.

When to stop: in late August or early September, leave the last round of coneflower and black-eyed Susan seedheads standing. Goldfinches eat the seed, and the stems protect the crowns over winter.

Cutting back hard

What it is: cutting flowering stems all the way down to the low rosette of leaves at the base of the plant.

When: right after the first flush finishes.

Best for: salvia 'May Night' and 'Caradonna', yarrow once its side buds are spent, and 'Rozanne' when the center has opened up badly.

What to expect: salvia regrows new flower spikes in about four to six weeks and blooms again in August. The second flush is usually a little shorter than the first.

One related technique belongs to a different set of plants. The early summer "Chelsea chop" used to keep tall asters and mums compact is a fall bloomer's trick, covered on our fall flowering perennials page along with the perennials that take over from September.

Planting a border that flowers from May to October

Long bloomers let a small bed carry color for five months with a handful of plants. Here is a 10 by 6 foot sunny bed for a zone 5 or 6 garden, deep enough for three rows once the back row reaches its full 3 to 4 foot spread:

• Back row: three Russian sage, spaced 3 feet apart, for July to September.
• Middle row: two geranium 'Rozanne' and two blanket flower, alternating at 2 to 2.5 feet, for June to October.
• Front row: three catmint 'Walker's Low' and two coreopsis 'Moonbeam', at about 2 feet, for May to September.

That is 12 plants with something in flower from late May until frost. The catmint opens the season, 'Rozanne' and blanket flower carry the summer, and Russian sage peaks just as the catmint rests after its shear. Use the plant spacing calculator to adjust the counts for a different bed size.

Long bloomers work hard, and they need steady water in their first summer to do it. Our watering guide covers how much and how often for new perennial beds.

For the full hardiness picture, including shade perennials, grasses and the plants that bloom only briefly but belong in every border, see perennials by zone. That page has the complete tables for each zone; this one pulls out only the long bloomers.

Long bloomers and deer

A border that flowers all summer also sits in front of deer all summer. Some of the best long bloomers are among the plants deer most reliably leave alone, and some are favorites.

• Usually skipped: catmint, Russian sage, yarrow, threadleaf coreopsis, agastache and lesser calamint, all protected by aromatic oils or fine, dry foliage. Our page on whether Russian sage is deer resistant explains why deer walk past it.
• Tested more often: geranium 'Rozanne', whose softer leaves get sampled more than other hardy geraniums, as our page on whether geraniums are deer resistant explains. Coneflower buds are also taken in dry Augusts, covered on are coneflowers deer resistant.
• Heavily browsed: daylilies of every kind, including rebloomers. Deer eat the flower buds, which wipes out the rebloom waves you worked for.

If deer visit your yard, build the long blooming border from the aromatic group and check each plant against our deer resistant perennials table before you buy.

FAQ

What perennial blooms the longest?

In zones 5 through 8, geranium 'Rozanne' is usually the longest blooming perennial, flowering from June until frost without deadheading. In zones 8 and 9, autumn sage and blue plumbago bloom even longer, often from spring into November. Catmint 'Walker's Low' comes close in colder zones if you shear it after the first flush.

Do perennials that bloom all summer need deadheading?

Some do and some don't. Low-seeding plants like 'Rozanne' and coreopsis 'Moonbeam' keep flowering without it. Blanket flower, pincushion flower, shasta daisy and reblooming daylilies slow down quickly unless spent flowers are removed. Catmint and threadleaf coreopsis need one shear rather than regular deadheading.

When should I cut back catmint to get it to rebloom?

Cut it back by about half when the first flush of flowers is two thirds faded, which is usually late June to early July. Water it deeply afterward. New growth appears within days, and a second full bloom follows in about three to four weeks, often lasting until frost in cooler climates.

Why did my reblooming daylilies stop blooming?

The usual causes are crowding, drought and seed pods. Clumps older than about five years compete with themselves and should be divided in spring. Rebloomers need steady water through summer to push new scapes. Removing spent flowers and finished scapes helps too, since seed pods divert energy from new buds.

What are the best long blooming perennials for shade?

Yellow corydalis is the most dependable, flowering from May to September in part shade. Most perennials that bloom all summer need at least six hours of sun, so in shade expect shorter bloom and plan on foliage plants for season-long interest. Geranium 'Rozanne' tolerates light afternoon shade in warm zones with somewhat fewer flowers.

Is blanket flower really a perennial?

Yes, but a short lived one. Blanket flower often lasts only two to three years, partly because it blooms so heavily and partly because it rots in wet winter soil. Plant it in lean, well drained ground, cut it back in late August to help it overwinter, and let a few seedheads drop so seedlings replace older plants.

Which long blooming perennials survive zone 3?

Catmint 'Walker's Low', common yarrow, threadleaf coreopsis, native blanket flower, 'Stella de Oro' and 'Happy Returns' daylilies, black-eyed Susan and coneflower are all rated to zone 3. Each can bloom for 10 weeks or more with the right deadheading or shearing, and all of them come back reliably after a hard northern winter.