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Aug 172012
 

Most perennials do not bloom throughout an entire growing season. Knowing the period of bloom will help with determination of plant combinations that provide color all summer long. Below are lists of perennials classified by their flowering time. The dates are approximate and will depend on geographical location. The warmer valleys of Idaho may provide blooming conditions for many plants as much as 6 weeks earlier than the cooler northern or mountainous regions.


Gaillardia

Blanket Flower blooms all summer

Perennials with Extended Blooming Times

These are the exceptional plants that bloom over several months through spring, summer, and fall.

Common Name Scientific Name Regional Adaptation
Anthemis (Dyer’s Chamomile) Anthemis tinctoria N, SW, SC, SE, HA
Aster Aster spp. N, SW, SC, SE, HA
Balloon Flower Platycodon grandiflorus N, SW, SC, SE, HA
Bee Balm Monarda didyma N, SW, SC, SE, HA
Bellflower Campanula spp. N, SW, SC, SE, HA
Blanket Flower Gaillardia . grandiflora N, SW, SC, SE, HA
Butterfly Weed Asclepias tuberose N, SW, SC, SE, HA
Cranesbill Geranium spp. N, SW, SC, SE, HA
Deadnettle Lamium maculatum N, SW, SC, SE, HA
Dianthus Dianthus spp. N, SW, SC, SE, HA
Flax Linum perenne, Linum grandiflorum N, SW, SC, SE, HA
Hollyhock Alcea rosea N, SW, SC, SE, HA
Lavender Lavendula angustifolia SW, SC
Pincushion Flower Scabiosa caucasica N, SW, SC, SE, HA
Potentilla Potentilla verna N, SW, SC, SE, HA
Russian Sage Perovskia atriplicifolia SW, SC
Shasta Daisy Leucanthemum x supermum N, SW, SC, SE, HA
Veronica Veronica spp. N, SW, SC, SE
Yarrow Achillea spp. N, SW, SC, SE, HA

Key to regional adaptation notes:
N = Northern Idaho valley locations in USDA zones 5 & 6, Moscow to Sandpoint.
SE = Southeastern Idaho valley locations in USDA zones 3 & 4 from Rexburg to Pocatello.
SC = South-central Idaho Magic Valley locations in USDA zones 4 & 5, Burley and Twin Falls.
SW = Southwestern Idaho Treasure Valley locations in USDA zones 5 & 6, Boise area (also Lewiston).
HA = High altitude (>5,000 ft) areas of central, southeastern Idaho and similar locations elsewhere.


Poppies

Poppies provide spring color. Courtesy of FreeFoto.com

Early-Blooming Perennials

These are plants that bloom in early spring, typically March (warm areas), April, and May.

Common Name Scientific Name Regional Adaptation
Bleeding Heart Dicentra spp. N, SW, SC, SE, HA
Bloodroot Sanguinaria canadensis N, SW, SC, SE, HA
Blue False Indigo Baptisia australis N, SW, SC, SE, HA
Bugleweed Ajuga reptans N, SW, SC, SE, HA
Candytuft Iberis sempervirens N, SW, SC, SE
Columbine Aquilegia spp. N, SW, SC, SE, HA
Delphinium Delphinium x elatum N, SW, SC, SE, HA
Dianthus Dianthus plumarius N, SW, SC, SE, HA
False Rock Cress Abrietia deltoidea N, SW, SC
Forget-Me-Not Anchusa myosotis N, SW, SC, SE, HA
Gas Plant Dictamnus albus N, SW, SC, SE, HA
Jacob’s Ladder Polemonium reptans N, SW, SC, SE, HA
Mountain Bluet Centaurea montana N, SW, SC, SE
Oriental Poppy Papaver orientalis N, SW, SC, SE, HA
Peony Paeonia spp. N, SW, SC, SE, HA
Phlox, Creeping Phlox subulata N, SW, SC, SE, HA
Prairie Smoke Geum triflorum N, SW, SC, SE, HA
Pussytoes Antennaria dioica N, SW, SC, SE, HA
Rock Cress Arabis caucasica N, SW, SC, SE, HA
Sea Pink (Sand Wort) Armeria maritime N, SW, SC, SE, HA
Snow-in-Summer Cerastium tomentosum N, SW, SC, SE, HA

Key to regional adaptation notes:
N = Northern Idaho valley locations in USDA zones 5 & 6, Moscow to Sandpoint.
SE = Southeastern Idaho valley locations in USDA zones 3 & 4 from Rexburg to Pocatello.
SC = South-central Idaho Magic Valley locations in USDA zones 4 & 5, Burley and Twin Falls.
SW = Southwestern Idaho Treasure Valley locations in USDA zones 5 & 6, Boise area (also Lewiston). HA = High altitude (>5,000 ft) areas of central, southeastern Idaho and similar locations elsewhere.


Asters

One of many summer blooming asters

Mid-Season Perennials

These are plants that bloom during the mid-summer months, typically June, July, and into August.

Common Name Scientific Name Regional Adaptation
Alumroot (Coral Bells) Heuchera sanguinea N, SW, SC, SE, HA
Aster Aster spp. N, SW, SC, SE, HA
Astilbe Astilbe x arendsii N, SW, SC, SE
Bee Balm Monarda didyma N, SW, SC, SE
Bellflower Campanula spp. N, SW, SC, SE, HA
Blanket Flower Gaillardia . grandiflora N, SW, SC, SE, HA
Butterfly Weed Asclepias tuberose N, SW, SC, SE, HA
Cardinal Flower Lobelia cardinalis N, SW, SC, SE, HA
Chrysanthemum Deudranthuna x grandiflora N, SW, SC, SE, HA
Deadnettle Lamium maculatum N, SW, SC, SE, HA
Coreopsis Coreopsis spp. N, SW, SC, SE
Flax Linum perenne N, SW, SC, SE, HA
Foxglove Digitalis purpurea N, SW, SC, SE
Gloriosa Daisy Rudbeckia x hybrida N, SW, SC, SE, HA
Goatsbeard Aruncus dioicus N, SW, SC, SE
Hollyhock Alcea rosea N, SW, SC, SE, HA
Larkspur Delphinium spp. N, SW, SC, SE, HA
Lavendar Lavandula angustifolia SW, SC
Lupine Lupinus spp. N, SW, SC, SE, HA
Penstemon Penstemon spp. N, SW, SC, SE, HA
Phlox Phlox spp. N, SW, SC, SE, HA
Pincushion Flower Scabiosa caucasica N, SW, SC, SE, HA
Red Valerian Centranthus rubber SW, SC
Russian Sage Perovskia atriplicifolia SW, SC
Sage Salvia officinalis N, SW, SC, SE, HA
Shasta Daisy Leucanthemun x superbum N, SW, SC, SE, HA
Silver Mound Artimisia schmidtiana N, SW, SC, SE, HA
Stoke’s Aster Stokesia laevis N, SW, SC, SE, HA
Sundrops (Evening Primrose) Oenothera fruticosa SW, SC, SE
Veronica Veronica spp. N, SW, SC, SE
Yarrow Achillea spp. N, SW, SC, SE, HA

Key to regional adaptation notes:
N = Northern Idaho valley locations in USDA zones 5 & 6, Moscow to Sandpoint.
SE = Southeastern Idaho valley locations in USDA zones 3 & 4 from Rexburg to Pocatello.
SC = South-central Idaho Magic Valley locations in USDA zones 4 & 5, Burley and Twin Falls.
SW = Southwestern Idaho Treasure Valley locations in USDA zones 5 & 6, Boise area (also Lewiston).
HA = High altitude (>5,000 ft) areas of central, southeastern Idaho and similar locations elsewhere.


Sundrops

Fall blooming sundrops or evening primrose

Late-Blooming Perennials

These are plants that bloom in late summer, continuing into fall, many blooming through the earliest frost events. The time period for bloom will typically be August, September, and in warm regions continuing into October.

Common Name Scientific Name Regional Adaptation
Aster Aster spp. N, SW, SC, SE, HA
Chrysanthemum Deudranthuna x grandiflora N, SW, SC, SE, HA
Coreopsis Coreopsis spp. N, SW, SC, SE, HA
Deadnettle Lamium maculatum N, SW, SC, SE, HA
Globe Thistle Echinops ritro N, SW, SC, SE, HA
Gloriosa Daisy Rudbeckia x hybrida N, SW, SC, SE, HA
Leadwort (Plumbago) Cerastostigma plumbagonoides N, SW, SC, SE, HA
Lavendar Lavandula angustifolia SW, SC
Mullein Verbascum spp. SW, SC, SE
Obedient Plant Physostegia virginiana N, SW, SC, SE, HA
Orange Coneflower Rudbeckia fulgida var. sullivantii N, SW, SC, SE
Phlox, Tall Phlox spp. N, SW, SC, SE, HA
Pincushion Flower Scabiosa caucasica N, SW, SC, SE, HA
Purple Coneflower Echinacea purpurea N, SW, SC, SE, HA
Red Hot Poker Kniphofia uvaria SW, SC
Russian Sage Perovskia atriplicifolia SW, SC
Sneezeweed (Helen’s Flower) Helenium autumnale N, SW, SC, SE, HA
Stonecrop Sedum spp. N, SW, SC, SE, HA
Sundrops (Evening Primrose) Oenothera fruticosa SW, SC, SE

Key to regional adaptation notes:
N = Northern Idaho valley locations in USDA zones 5 & 6, Moscow to Sandpoint.
SE = Southeastern Idaho valley locations in USDA zones 3 & 4 from Rexburg to Pocatello.
SC = South-central Idaho Magic Valley locations in USDA zones 4 & 5, Burley and Twin Falls.
SW = Southwestern Idaho Treasure Valley locations in USDA zones 5 & 6, Boise area (also Lewiston). HA = High altitude (>5,000 ft) areas of central, southeastern Idaho and similar locations elsewhere.

 August 17, 2012