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  HOME:    HERBACEOUS ORNAMENTALS :   PERENNIALS

  ANNUALS
Introduction
Plant Selection
Hardy, Semi-hardy, Tender
Heat and Drought Tolerant
Shade Tolerant Annuals
Fragrant Annuals
Ornamental Foliage
Climbing Annuals
Hanging Baskets
Cut Flowers
Planting
Starting Plants
Maintenance
Insects Problems
Disease Problems

PERENNIALS
Introduction
Plant Selection
Plant Dimension Characteristics
Specific Site Conditions
Classification by Bloom Periods
Perennials That Attract Wildlife
Planting
Starting Plants
Care and Maintenance

BULB FLOWERS
Introduction
Plant Selection
Planting Bulbs
Purchasing Bulbs
Care & Maintenance

ORNAMENTAL GRASSES
Introduction
Plant Selection
Mature Size
Grasses for Specific Uses
Planting Ornamental Grasses
Obtaining Plants
Care & Maintenance

CONTAINER GARDENING
Introduction
Container Selection
Soil Mixes
Container Placement
Plant Selection
Plant Care

Plant Dimension Characteristics

Tall Perennials: Tall plants can be used to hide foundations or other unattractive landscape features. They also make good backdrops for shorter perennials or annuals. Many tall perennials can be leggy or have sparse foliage, meaning they are at their best when planted with or behind shorter, denser plants. Tall perennials suitable for planting in Idaho include:

Red hot poker loves heat
Red Hot Poker is a tall perennial that loves heat
Courtesy of FreeFoto.com

Common Name Scientific Name Regional Adaptation
Aster Aster spp. N, SW, SC, SE, HA
Bee Balm Monarda didyma N, SW, SC, SE
Blue False Indigo Baptisia australis N, SW, SC, SE, HA
Butterfly Weed Asclepias tuberose N, SW, SC, SE, HA
Cardinal Flower Lobelia cardinalis N, SW, SC, SE, HA
Chrysanthemum (tall varieties) Deudranthuna x grandiflora N, SW, SC, SE, HA
Columbine Aquilegia spp. N, SW, SC, SE, HA
Foxglove Digitalis purpurea N, SW, SC, SE
Gas Plant Dictamnus albus N, SW, SC, SE, HA
Globe Thistle Echinops ritro N, SW, SC, SE, HA
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
Japanese Anenome Anenome x hybrida N, SW, SC, SE, HA
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
Oriental Poppy Papaver orientalis N, SW, SC, SE, HA
Penstemon Penstemon spp. N, SW, SC, SE, HA
Peony Paeonia lactiflora N, SW, SC, SE, HA
Purple Coneflower Echinacea purpurea N, SW, SC, SE, HA
Red Hot Poker Kniphofia uvaria SW, SC
Red Valerian Centranthus ruber SW, SC
Russian Sage Perovskia atriplicifolia SW, SC
Sage Salvia officinalis N, SW, SC, SE, HA
Sneezeweed (Helen’s Flower) Helenium autumnales N, SW, SC, SE, HA
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.

Forget-me-not has a sky blue flower
Forget-Me-Not has a sky blue flower

Short and Medium Perennials: These plants can be mixed with taller perennials and also used in rock gardens and borders. Medium-sized perennials suitable for use in Idaho include:

Common Name Scientific Name Regional Adaptation
Alumroot (Coral Bells) Heuchera sanguinea N, SW, SC, SE, HA
Astilbe Astilbe x arendsii N, SW, SC, SE
Balloon Flower Platycodon grandiflorus N, SW, SC, SE, HA
Bellflower Campanula spp. N, SW, SC, SE, HA
Blanket Flower Gaillardia . grandiflora N, SW, SC, SE, HA
Bleeding Heart Dicentra spp. N, SW, SC, SE, HA
Candytuft Iberis sempervirens N, SW, SC, SE
Chrysanthemum (short varieties) Deudranthuna x grandiflora N, SW, SC, SE, HA
Dianthus Dianthus spp. N, SW, SC, SE, HA
Coreopsis Coreopsis spp. N, SW, SC, SE, HA
Flax Linum perenne N, SW, SC, SE, HA
Forget-Me-Not Anchusa myosotis N, SW, SC, SE, HA
Hosta Hosta spp. N, SW, SC, SE, HA
Jacob’s Ladder Polemonium reptans 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
Mountain Bluet Centaurea montana N, SW, SC, SE
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
Rock Cress Arabis caucasica N, SW, SC, SE, HA
Silver Mound Artimisia schmidtiana N, SW, SC, SE, HA
Stoke’s Aster Stokesia laevis N, SW, SC
Stonecrop Sedum spp. N, SW, SC, SE, HA
Sundrops Oenothera fruticosa N, SW, SC, SE
Veronica Veronica spp. N, SW, SC, SE, HA
Shasta Daisy Leucanthemun x superbum 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.

False rock cress
False Rock Cress is an outstanding rock garden specimen
Courtesy of FreeFoto.com

Groundcover Perennials: These plants develop greater spread than height and can be used in many landscape situations where low growth and coverage are needed, including rock gardens. Below is a list of groundcover perennials suitable for Idaho:

Common Name Scientific Name Regional Adaptation
Beach Wormwood Artimisia stelleriana N, SW, SC, SE, HA
Bishop’s Goutweed Aegopodium podograria N, SW, SC, SE, HA
Bugleweed Ajuga reptans N, SW, SC, SE, HA
Cranesbill Geranium spp. N, SW, SC, SE, HA
Deadnettel Lamium maculatum N, SW, SC, SE, HA
Hosta Hosta spp. N, SW, SC, SE, HA
False Rock Cress Aubrieta deltoidea N, SW, SC
Lamb’s Ear Stachys byzantina N, SW, SC, SE
Leadwort (Plumbago) Cerastostigma plumbaginoides N, SW, SC
Periwinkle Vinca minor N, SW, SC, SE, HA
Potentilla Potentilla verna N, SW, SC, SE, HA
Pussytoes Antennaria dioica N, SW, SC, SE, HA
Red Barrenwort Epimedium x rubrum N, SW, SC
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
Sweet Woodruff Asperula odorata 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.

 


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