Summer Dormancy: Why Plants Disappear in the Heat

Why Do Some Plants 'Disappear' In The Heat?

Summer dormancy explained and fixed at nature hills garden blog

It's the dog days of summer! These hot days and soaring temps can leave gardeners wondering, "Where did my plants go?".

Gardeners from all climates are left puzzled during peak summer and heatwaves when once-thriving plants suddenly wither, turn yellow, or vanish altogether. So, if you are out in your garden, sweating and scratching your head while looking at a brown, shriveled pile of leaves where your plant once was - don't panic!

This puzzling vanishing act isn't necessarily a plant catastrophe. It's actually a clever trick of nature known as summer dormancy.

Some of our favorite cool-season beauties, spring ephemerals, and more delicate plants are adapted to bloom early and retreat underground once the summer sun cranks up the heat. They aren't dying; they're resting!

Don't run out and grab new plants just yet! mother nature has taught these plants to grow while the canopy's still open and the soil is moist, then go quiet when the competition heats up. Understanding these disappearing acts can help you design a more balanced landscape that stays lively from spring through fall.

What Is Summer Dormancy?
Common Plants That Go Dormant In Summer
What You Can Do
Plants That Stand Up To The Heat
Landscape Tips & Summer Garden Care
Helping Lawns That Go Dormant In Summer

What Is Summer Dormancy?

Summer dormancy is the botanical version of a siesta. Plants enter a temporary resting state when growing conditions become less favorable, typically due to heat, drought, or intense sunlight. This adaptation is especially common for spring ephemerals, which grow, flower, and set seed quickly before slipping back into dormancy during summer's sizzle.

Why Summer-Dormancy Happens:

Moisture conservation: In nature, dry summers make growth hard. Dormancy protects the plant.
Life cycle timing: Spring ephemerals take advantage of early light, flower quickly, and then vanish once the summer sun is too intense.
Heat avoidance: High temperatures stress delicate roots and foliage, so plants retreat underground where it's cooler.
Plants that dry out excessively during heat waves and prolonged drought.

Common Plants That Go Dormant In Summer

plants that go dormant in summer infographic

Spring Ephemerals: A broad group of woodland wildflowers and spring-flowering bulbs such as Bloodroot, Mayapple, and Toothwort, but also Tulips, Daffodils, and Hyacinths, etc. Often appear in early spring and vanish by summer.
Bleeding Heart (Dicentra spectabilis): Dies back completely after blooming in spring. Its ferny foliage yellows and disappears, leaving no trace by mid-summer.
Virginia Bluebells (Mertensia virginica): Delicate bell-like blooms in spring, but gone without warning by early summer.
Dutchman's Breeches (Dicentra cucullaria): A woodland wildflower with whimsical flowers that vanishes just as quickly as it appeared.
Bleeding Heart (Dicentra spectabilis): Arching stems of heart-shaped blooms in spring fade fast once heat sets in. The soft, ferny foliage yellows and disappears completely
Trout Lily (Erythronium americanum): With mottled leaves and dainty yellow blooms, this ephemeral fades fast once the trees leaf out.
Columbine (Aquilegia spp.): Graceful spurred blooms in spring, often followed by a summer die-back in hot, dry climates. May self-sow and return reliably
Oriental Poppy (Papaver orientale): Brilliant spring bloomers that often go completely dormant after flowering, with foliage yellowing and disappearing
Jacob’s Ladder (Polemonium caeruleum): Cool-season perennial that blooms in spring and can die back in summer heat
Corydalis (Corydalis lutea and others): Can enter dormancy in mid-summer after a spring flush of yellow or blue flowers

What You Can Do

Don’t dig them up! If you notice a bare spot where lush spring growth once stood, mark it and leave the soil undisturbed. Most summer-dormant plants will return reliably each year if left alone. Sometimes even regrowing later that fall, once temperatures cool down!

Helpful tips for summer dormant plant care:

Avoid excessive watering since too much can rot the roots during dormancy.
Mark dormant spots with a decorative stake or rock.
Surround spring bloomers with heat-tolerant perennials or shrubs to fill the visual gap.
Apply arborist mulch to help keep the soil cool and reduce evaporation. Learn more about how and why to mulch your plants.

Plants That Stand Up To The Heat

Looking to keep your beds vibrant while your spring beauties snooze? These sun-loving summer-flourishing plants can be tucked nearby to take over the stage once the ephemerals exit. They won't just tolerate the heat; they thrive in it!

Summer Stars to Try Instead

Coneflower (Echinacea spp.)

Bold blooms, great for pollinators
Deep roots and daisy-like flowers stand tall in full sun
Symbolizes strength and healing in Native traditions

Coreopsis (Coreopsis verticillata)

Fine-textured foliage with golden blooms
Low maintenance and drought-tolerant
Long bloom time keeps beds lively

Russian Sage (Perovskia atriplicifolia)

Aromatic silvery stems with lavender-blue plumes
Loves heat and poor soil
Adds hazy motion and soft color to summer beds

Black-Eyed Susan (Rudbeckia hirta)

Iconic sunny yellow flowers with a dark center
Thrives in heat, draws butterflies
Native to many regions and reseeds itself

Blanket Flower (Gaillardia x grandiflora)

Red, orange, and gold blooms with a long blooming season
Thrives in rocky, dry spots
Cheerful, rugged, and a true heat lover

Daylily (Hemerocallis spp.)

Easygoing clumps with strappy leaves and bold trumpet blooms
Each flower lasts just a day, but plants bloom for weeks
Comes in a rainbow of colors and tolerates a range of soils

Yarrow (Achillea millefolium)

Flat-topped flower clusters loved by pollinators
Ferny, aromatic foliage that handles drought like a champ
Long bloom period and useful in cut arrangements

Salvia (Salvia nemorosa and hybrids)

Spikes of purple, pink, or blue flowers loved by bees and hummingbirds
Reblooms with a quick trim
Aromatic and deer resistant

Sedum (Sedum spectabile, now Hylotelephium)

Succulent stems and leaves with late-summer flower heads
Fantastic in rock gardens or xeriscapes
Holds structure and color well into fall. Learn how to rock garden here!

Hyssop (Agastache spp.)

Tall spikes of tubular blooms in coral, purple, or pink
Fragrant minty foliage that repels deer and attracts pollinators
Loves heat and dry soil with good drainage
A favorite of hummingbirds and perfect for sunny borders

Landscape Tips & Summer Garden Care

By planting in layers, you can ensure something is always stealing the spotlight. Use spring ephemerals as underlayers and surround or interplant them with later bloomers like Salvia, Sedum, or Daylilies. You'll have seamless seasonal beauty without holes in your garden design.

If you're exploring edible landscaping, leafy greens like Arugula and Lettuce can also bolt and disappear in summer heat. Replace them with Basil, Peppers, or Eggplant for a bold, tasty transition. Get edible gardening design tips here.

Care Tips For Summer Gardens

Deadhead summer bloomers to keep color going strong and to keep the energy going to the leaves and roots instead of producing seeds. Learn how to deadhead for more blooms.
Water deeply and less frequently, checking moisture with the Finger Test before watering.
Use companion planting and perennials for long-lasting structure. Learn about planting perennials.
Tuck spring ephemerals and other small early bloomers beneath or around larger plants that emerge later in the season. As early growers fade and go dormant, the larger plants fill in naturally, covering bare spots, shading the more delicate plants' roots, and keeping the garden full and lively!

Helping Lawns That Go Dormant In Summer

summer dormancy in lawns and how to fix it

Just like certain flowering plants, lawn grasses can also go dormant when temperatures soar. This is especially true for cool-season grasses like Kentucky Bluegrass, Perennial Ryegrass, and Tall Fescue. These types grow best in spring and fall, but often turn tan and stop growing during mid-summer heat, especially if moisture is limited.

Why cool-season grasses go dormant in summer:

High temps (above 85°F) and lack of rain trigger dormancy
The grass slows its growth to conserve water
Roots remain alive underground, even if the blades go brown

How to Reduce Summer Lawn Dormancy:

Water deeply and less frequently to encourage deep root growth (learn how here)
Mow higher to shade the roots and retain moisture
Use drought-tolerant, improved seed blends for added resilience
Avoid fertilizing during hot months, which stresses dormant grass

Blend It Smart: Mixed-Season Lawns for Year-Round Green

If you're in one of those tricky transitional zones with frigid winters and blazing summers, your lawn doesn't have to suffer on either end. Consider planting a mixed lawn using plugs or seed that combines cool-season grasses (for spring/fall vigor) with warm-season species like Bermuda Grass or Zoysia that shine in summer.

This approach ensures:

Cool-season color in spring and fall
Warm-season performance in the summer heat
Year-round visual interest and fewer brown patches
Greater drought and temperature tolerance overall

helping gardens through the dog days of summer

Pro tip: Blended seed mixes or plug kits designed for four-season lawns are now available. They adapt to shifting weather patterns while maintaining a healthy look even in extreme conditions.

A Little Vanishing Act Isn't So Mysterious After All!

Though it may feel like a summer disappearing act, many plants are simply taking a heat break underground. By pairing spring ephemerals with tough summer bloomers, you'll create a thriving landscape that keeps the rhythm going no matter the season!

Just remember, when the Bleeding Hearts take a bow, it's someone else's turn to shine.

Happy Planting!

Old Fashioned Bleeding Heart

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Virginia Bluebell

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Perennial

Nature Hills Nursery

American Beauties

Flower Color

Pink
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Growing Zone Range

3-9

4-9

Mature Height

1-2 ft

Width

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Frequently Asked Questions

Why do some plants go dormant in summer instead of winter?

Some plants go dormant in summer rather than winter because their life cycle is timed around cool, moist conditions, not cold temperatures. Spring ephemerals and cool-season plants evolved to grow, flower, and set seed quickly in early spring while the soil is moist and light reaches the ground, then retreat underground once summer heat and drought make growth difficult or impossible. This heat-driven dormancy is a survival strategy, not a sign of plant death, so resist the urge to dig up bulbs or pull plants that appear to have vanished. Plan your garden with summer-blooming perennials or annuals to fill the gaps left by dormant plants and keep your landscape looking full through the season.

How can you tell if a plant is dormant or actually dying in summer heat?

Summer dormancy and plant death can look nearly identical at first glance, but the key difference lies below the soil surface. A dormant plant will have firm, healthy roots or intact bulbs when gently investigated, while a dying plant typically shows mushy, rotted, or completely desiccated root tissue. Timing is also a strong clue: if your Bleeding Heart, Daffodils, or other known spring ephemerals fade and collapse in June or July after a full season of growth and flowering, dormancy is almost certainly the cause. Before digging anything up or replacing plants, wait until fall, water the area lightly, and watch for signs of regrowth before making any decisions.

Which types of plants are most likely to go dormant during summer?

Plants most likely to go summer dormant include spring ephemerals, cool-season bloomers, and delicate woodland species that evolved to complete their life cycle before summer heat peaks. Common examples include Bleeding Heart (Dicentra spectabilis), Tulips, Daffodils, Hyacinths, and woodland wildflowers like Bloodroot, Mayapple, and Toothwort. These plants typically emerge in early spring, flower quickly, and begin dying back by late spring to early summer once temperatures rise and soil moisture drops. Plan your garden to include heat-tolerant summer performers in the same beds so you maintain visual interest after these early bloomers retreat.

When do summer dormant plants wake up and start growing again?

Summer dormant plants typically begin to reemerge in late summer to early fall as temperatures cool and soil moisture increases. Spring ephemerals like bleeding heart and daffodils will show new foliage once conditions become favorable again, often September through October in most temperate zones. To support their return, keep the area lightly watered during dormancy and avoid disturbing the soil where bulbs and roots are resting underground.

How should you water plants that are going through summer dormancy?

During summer dormancy, most plants need significantly reduced watering since their metabolic activity has slowed and overwatering dormant roots can cause rot. For spring-flowering bulbs and ephemerals like tulips and bleeding heart, allow the soil to dry out between waterings and aim for no more than once every two to three weeks if rainfall is absent. Check the soil a few inches down before watering, and if it still feels moist, hold off. When in doubt, err on the side of too dry rather than too wet, and resume a normal watering schedule once cooler fall temperatures prompt new growth.

Does grass go dormant in summer and will it green up again on its own?

Yes, grass absolutely goes dormant in summer, and it is a completely natural survival response to heat and drought stress. Cool-season grasses like fescue, bluegrass, and ryegrass are especially prone to summer dormancy, typically going brown when temperatures consistently exceed 90 degrees Fahrenheit or when rainfall is scarce for three to four weeks or more. The good news is that healthy turf will green up again on its own once cooler temperatures and moisture return in fall, usually around September or October depending on your region. To support recovery, avoid heavy foot traffic on dormant turf, hold off on fertilizing until it greens back up, and water deeply but infrequently (about one inch per week) if you want to maintain some green color through the hottest months.

How do you care for a garden when your plants go summer dormant?

When plants go summer dormant, resist the urge to overwater or fertilize, as this can rot dormant roots or force vulnerable new growth during stressful conditions. Mark the locations of dormant plants so you avoid accidentally digging them up, and fill the gaps with heat-tolerant summer performers like coneflowers, black-eyed Susans, or ornamental grasses. Allow the foliage to die back naturally before removing it, since the leaves help the plant store energy for next season. Plan your garden design around these predictable cycles by pairing spring ephemerals with later-emerging perennials that will cover bare spots once dormancy sets in.

Which cool season plants typically die back when summer heat arrives?

Many cool-season plants are programmed to die back when summer heat arrives, including spring ephemerals like Bloodroot, Mayapple, and Toothwort, as well as popular spring bulbs such as Tulips, Daffodils, and Hyacinths. Bleeding Heart (Dicentra spectabilis) is another classic example, disappearing completely once temperatures climb. This summer dormancy is a natural survival strategy, not a sign of plant death, so resist the urge to dig up these plants or fill their spots with something new. Plan ahead by interplanting these early-season performers with later-emerging perennials or annuals that will fill the gaps as summer unfolds.

Should you cut back plants that have gone dormant in summer?

Once a summer-dormant plant like Bleeding Heart or spring bulbs has fully yellowed and died back, you can trim the foliage down to the ground. Do not cut it back while any green remains, as the leaves are still feeding the roots below. Mark the spot so you do not accidentally dig into the dormant root system when filling gaps with summer annuals or perennials.

How do you know when a summer dormant plant is ready to come out of dormancy?

Summer dormant plants typically begin to re-emerge as temperatures cool and soil moisture increases in late summer or early fall, often triggered when daytime highs drop consistently below 75 to 80 degrees Fahrenheit. For spring ephemerals and bulbs, this usually coincides with the first reliable rains of late summer or early autumn, signaling that conditions are favorable for root activity to resume. Watch the soil around the plant's crown or marked location for small shoots or swelling buds pushing through, which is your clearest sign that dormancy is ending. In the meantime, keep the area lightly watered during extended dry spells and avoid disturbing the soil where dormant roots are resting.

Unraveling The Mystery Of Summer Dormancy