Rocky Mountain
Perennial Bloom Guide
 

* as provided in the Colorado Nursery & Greenhouse Association

PLANT

BLOOM TIME

XERIC

GROUND COVERS

Creeping Oregon Grape Holly

March

Yes

Barren Strawberry

Apr-May

Yes

Sweet Violet

Apr-May

Creeping Phlox

Apr-Jun

Speedwell

Apr-Jun

Yes

Sweet Woodruff

Apr-Jun

Mock Strawberry

May

Yes

Scotch or Irish Moss

May

Carpet Bugle

May-Jun

Cranesbill

May-Jun

Creeping Buttercup

May-Jun

Dead Nettles

May-Jun

Kinnikinnick

May-Jun

Yes

Periwinkle

May-Jun

Pussytoes

May-Jun

Yes

Self Heal

May-Jun

Yes

Snow in Summer

May-Jun

Yes

Soapwort

May-Jun

Yellow Archangel

May-Jun

Yellow Iceplant

May-Jun

Yes

Maiden Pinks

May-July

Strawberry

May-July

Yes

Creeping Potentilla

May-Aug

Creeping Tickseed

May-Aug

Thyme

May-Aug

Yes

Stonecrop

May-Sep

Yes

Snow on the Mtn

Jun

Moneywort

Jun-Jul

Mexican Evening Primrose

Jun-Aug

Yes

Prairie Winecup

Jun-Aug

Yes

Woolly Yarrow

Jul-Aug

Yes

Creeping St. Johnswort

Jul-Sep

Desert Paper Flower

Jul-Oct

Yes

Himalayan Border Jewel

Aug-Sep

"Plumbago, Leadwort"

Aug-Sep

Purple Leaf Wintercreeper

Sep-Oct

BIENNIALS

Sweet William

Apr-Jul

"Honesty, Money Plant"

Apr-Jun

Canterbury Bells

May-Jun

English Wallflower

May-Jul

Iceland Poppy

May-Jul

Yes

Clary Sage

Jun-Jul

Foxglove

Jun-Aug

Chocolate Flower

Jun-Sep

Yes

Mullein

Jun-Oct

Yes

Chinese Angelica

Jul-Sep

Prairie Coneflower

Jul-Oct

Yes

Gloriosa Daisy

Aug-Sep

Yes

GRASSES

Blue Avena or Blue Oat

Jun-Aug

Fescue

Jun-Aug

Yes

Little Bluestem

Jun-Aug

Yes

Fountain Grass

Jul

Switch Grass

Jul

Yes

Indian Grass

Jul-Aug

Yes

Moor Grass

Jul-Aug

Big Bluestem

Jul-Sep

Yes

Feather Reed Grass

Jul-Sep

Northern Sea Oats

Jul-Sep

Maiden or Miscanthus Grass

Aug-Sep

Plume or Ravenna Grass

Aug-Sep

Yes

Giant Reed

Sep-Oct

BULBS

Common Snowdrop

Feb-Mar

Crocus

Feb-Mar

Winter Aconite

Feb-Mar

Netted Iris

Feb-Apr

Yes

Glory of the Snow

Mar

Striped Squill

Mar

Yes

Grape Hyacinth

Mar-Apr

Yes

Spring Snowflake

Mar-Apr

"Daffodil, Narcissus, Jonquil"

Mar-May

Tulip

Mar-Jun

Yes

Wind Flower

Apr

Dutch Hyacinth

Apr-May

Siberian Squill

Apr-May

Yes

Star of Bethlehem

Apr-May

Crown Imperial

May-Jun

Ornamental Onion

May-Jun

Garden Lily

Jun-Aug

Italian Arum

Aug-Feb

"Resurrection Lily, Naked Lady"

Aug-Sep

Yes

"Meadow Saffron, Autumn Crocus"

Sep

BORDER

Lenten Rose

Feb-May

Basket of Gold

Apr-May

Yes

False Forget Me Not

Apr-May

Spotted Bethlehem Sage

Apr-May

Cushion Spurge

May

Leopard's Bane

May

Bleeding Heart

May-Jun

Catmint

May-Jun

Yes

Golden Banner

May-Jun

Columbine

May-Jun

Flax

May-Jun

Yes

Hardy Gloxinia

May-Jun

Heart leaved Bergenia

May-Jun

(Border Continued)

"Iris, Tall Bearded"

May-Jun

Yes

Lady's Mantle (Alchemilla)

May-Jun

Oriental Poppy

May-Jun

Yes

Peony

May-Jun

Purple Mullein

May-Jun

Yes

Snowdrop Anemone

May-Jun

Lupine

May-Jul

Maltese Cross

May-Jul

Painted Daisy

May-Jul

Potentilla

May-Jul

Yes

"Snowy Tansy, Snow Daisy"

May-Jul

Yes

Fern-leaved Bleeding Heart

May-Aug

Garden Carnation

May-Aug

Spike Speedwell

May-Aug

Yarrow

May-Sep

Yes

Knautia

May-Frost

Yes

False Indigo

Jun

Gasplant

Jun

"Giant Kale, Colewort"

Jun

Goat's Beard

Jun

"Iris, Siberian"

Jun

Marshall Chamomile

Jun

Yes

Alumroot

Jun-Jul

Butterfly Weed

Jun-Jul

Yes

Cranesbill

Jun-Jul

Cupid's Dart

Jun-Jul

Fireweed

Jun-Jul

Globeflower

Jun-Jul

"Italian Alkanet, Bugloss"

Jun-Jul

Jacob's Ladder

Jun-Jul

Spiderwort

Jun-Jul

Beard Tongue

Jun-Aug

Yes

Avens

Jun-Aug

Balloon Flower

Jun-Aug

Yes

Cornflower

Jun-Aug

"Double Bubble Mint, Mtn Mint"

Jun-Aug

Yes

Jupiter's Beard

Jun-Aug

Torch Lily

Jun-Aug

Yes

Bellflower

Jun-Sep

Blanket Flowers

Jun-Sep

Yes

Coralbells

Jun-Sep

Yes

Delphinium

Jun-Sep

Hollyhock Mallow

Jun-Sep

Ornamental Oregano

Jun-Sep

Salvia

Jun-Sep

Yes

Shasta Daisy

Jun-Sep

Threadleaf Coreopsis

Jun-Sep

Tree Mallow

Jun-Sep

Yes

Twinspur

Jun-Sep

Coreopsis

Jun-Oct

Ozark Sundrops

Jun-Oct

Yes

Pincushion Flower

Jun-Oct

Rose Campion

Jun-Oct

Yes

Bee Balm

Jul-Aug

Yes

Daylily

Jul-Aug

Yes

Dragonhead

Jul-Aug

False Sunflower

Jul-Aug

Yes

Gayfeather

Jul-Aug

Globe Thistle

Jul-Aug

Great Lobelia

Jul-Aug

Hollyhock

Jul-Aug

Yes

Hosta

Jul-Aug

Meadow Rue

Jul-Aug

Miniature Hollyhock

Jul-Aug

Plume Popply

Jul-Aug

Shepherd's Crook

Jul-Aug

Showy Fleabane

Jul-Aug

Yes

Stokes Aster

Jul-Aug

Tall Garden Phlox

Jul-Aug

Yes

Foxglove

Jul-Aug

Blackberry Lily

Jul-Sep

Coneflower

Jul-Sep

Yes

Daisy Mum

Jul-Sep

German Saponaria

Jul-Sep

Goldenrod

Jul-Sep

Yes

Ligularia

Jul-Sep

Monkshood

Jul-Sep

Native Four O'Clock

Jul-Sep

Yes

Obedient Plant

Jul-Sep

Sea Lavender

Jul-Sep

Yes

Whirling Butterflies

Jul-Sep

Yes

"Wormwood, Mugwort, White Sage"

Jul-Sep

Yes

California Fuchsia

Jul-Oct

Yes

"Aster, Michaelmas Daisy"

Jul-Frost

Inula

Aug

Baby's Breath

Aug-Sep

Yes

Black Snakeroot or Bugbane

Aug-Sep

Black-eyed Susan

Aug-Sep

Yes

Boltonia

Aug-Sep

Common Sneezeweed

Aug-Sep

"Marsh Mallow, Hardy Hibiscus"

Aug-Sep

Russian Sage

Aug-Sep

Yes

Siberian Skullcap

Aug-Sep

Yes

Tall Sedum

Aug-Sep

Yes

Culver's Physic

Aug-Oct

Garden Mum

Aug-Oct

New York Ironweed

Aug-Oct

"Windflower, Japanese Anemone"

Aug-Oct

General Guidelines for Growing Perennials Successfully

Planting Tips

  • Purchase plants 3-5 days before planting and let acclimate to climate
  • Water plants 4-6 hours prior to planting
  • Loosen pot-bound roots
  • Pinch leggy plants to promote sturdy growth
  • Avoid planting in soggy soil
  • Water thoroughly after planting and as needed to establish

Soil Amendment

  • Remove weeds from planting area
  • Till or spade area to loosen soil
  • Add organic amendment (compost) to all soils
  • Incorporate a high phosphorous fertilizer
  • Native plants may need less organic matter for healthy growth

Maintenance Tips

  • Water well in dry periods, but avoid over watering
  • Avoid overhead watering to prevent disease and flower damage
  • Remove spent flowers to promote rebloom and new growth
  • Cut back scruffy plants to promote fresh attractive growth
  • Stake tall plants early to provide needed support
  • Control pests and diseases as needed
  • Divide perennials when plants begin to decline from old age, overgrowth or diminished bloom
  • Perennials benefit from regular fertilization
  • Mulching - applying a mulch of compost in the summer will suppress weeds, maintain soil tilth and conserve moisture
  • Avoid drastic removal of late season growth in the fall - this will help protect plants through the winter

This outline was designed to help track when plants bloom to establish all season color. Further research can be obtained through the Rocky Mtn guide for color, size and planting tips. The guide also includes an extensive list of Water Plants, Rock Garden Varieties & Herbs.

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