Why Do Some Plants 'Disappear' In The Heat?
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! Ma 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:
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Moisture conservation: In nature, dry summers make growth hard. Dormancy protects the plant.
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Life cycle timing: Spring ephemerals take advantage of early light, flower quickly, and then vanish once the summer sun is too intense.
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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
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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.
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Bleeding Heart (Dicentra spectabilis): Dies back completely after blooming in spring. Its ferny foliage yellows and disappears, leaving no trace by mid-summer.
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Virginia Bluebells (Mertensia virginica): Delicate bell-like blooms in spring, but gone without warning by early summer.
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Dutchman's Breeches (Dicentra cucullaria): A woodland wildflower with whimsical flowers that vanishes just as quickly as it appeared.
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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
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Trout Lily (Erythronium americanum): With mottled leaves and dainty yellow blooms, this ephemeral fades fast once the trees leaf out.
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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
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Oriental Poppy (Papaver orientale): Brilliant spring bloomers that often go completely dormant after flowering, with foliage yellowing and disappearing
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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
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
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!
