UI Extension Master Gardeners UI Extension Events UI Extension Idaho Landscapes and Gardens Seasonal Topics UI Extension Idaho Landscapes and Gardens Get Answers UI Extension Idaho Landscapes and Gardens UI Extension Idaho's Growing Regions University of Idaho Extension UI Extension Idaho Landscapes and Gardens UI Extension Idaho Landscapes and Gardens Image Map
Aug 172012
 

Bulbs can be categorized into groups, based on growth characteristics or intended use, making selection easier. Useful groupings include season of bloom and hardiness.


Daffodils

Daffodils are among the favorite spring bulbs

Spring Flowering Bulbs

When considering bulbs, most people think of the common spring blooming flowers, including the crocus, daffodil, and tulip. These are plants that emerge relatively early in the spring, bloom for a short period of time, then die back and wait for next spring to repeat the process. These bulbs are usually hardy under most Idaho conditions and once planted need minimal care. Spring bulbs suitable for planting in Idaho include:

Common Name
Scientific Name
Relative Bloom Time
Regional Adaptation
Anemone Anemone Blanda Mid-spring N, SW, SC
Cammassia Cammassia leichtlinii Late spring N, SW, SC, SE
Chionodoxa Chionodoxa forbesii Early spring N, SW, SC, SE, HA
Crocus Crocus spp. Very early to mid-spring N, SW, SC, SE, HA
Daffodil Narcissus spp. Early to late spring N, SW, SC, SE, HA
Fritillaria Fritillaria spp. Mid-spring N, SW, SC, SE
Grape Hyacinth Muscari armeniacum Early to mid-spring N, SW, SC, SE, HA
Hyacinth Hyacithus orientalis Early spring N, SW, SC
Iris Iris spp. Late spring N, SW, SC, SE
Leucojum Leucojum aestivum Mid-springm N, SW, SC, SE
Ornamental Onion Allium spp. Late spring N, SW, SC, SE
Ornithogalum Ornithogalum umbellatum Late spring N, SW, SC
Pink Buttercups Oxalis adenophylla Late spring N, SW, SC
Puschkinia Puschkinia libanotica Mid-spring N, SW, SC, SE, HA
Snowdrops Galanthus nivalis Very early spring N, SW, SC, SE, HA
Squill scilla siberica Early to late spring N, SW, SC, SE, HA
Tulip Tulipa spp. Mid to late spring N, SW, SC, SE, HA
Trout Lily Erythronium spp. Mid-spring N, SW, SC, SE, HA
Winter Aconite Eranthis cilicium Very early spring 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.


lily

Many lily species grow well in Idaho

Summer Flowering Bulbs

Summer bulbs provide color after the spring flowers have stopped blooming. Many of them bridge the gap between spring bulbs and other perennials. Others bloom late into the summer. Summer bulbs are a mixture of those hardy in Idaho and those that are not hardy and must be treated as annuals. Non-hardy bulbs can be unearthed and stored for replanting the next year. Most of the tender summer bulbs are not recommended for planting in the shortest season areas of Idaho because of the potential for frost injury. For more information on storing tender bulbs overwinter, view this North Dakota Extension article.

Common Name
Scientific Name
Relative Bloom Time
Regional Adaptation
Bulbs Hardy in Idaho*
Arum Arum italicum Early Summer N, SW
Brodiaea Brodiaea laxa Early summer N, SW
Foxtail Lily Eremurus spp. Early summer N, SW, SC
Hardy Gladiolus Gladiolus nanus Mid-summer N, SW, SC, SE
Iris Iris spp. Early summer N, SW, SC, SE
Ixiolirion Ixiolirion pallasii Early summer N, SW, SC
Lily Lillium spp. Early to late summer N, SW, SC, SE
Ornamental Onion Alliums spp. Early summer N, SW, SC, SE
Ornithogalum Ornithogalum umbellatum Early summer N, SW, SC
Peonies Paeonia x hybrida Early summer N, SW, SC, SE, HA
Tender Summer Bulbs Grown as Annuals*
Begonia Begonia spp. Mid to late summer N, SW, SC, SE
Canna Canna spp. Late summer N, SW, SC, SE
Caladium Caladium spp. (colorful foliage) N, SW, SC, SE
Dahlia Dahlia spp. Mid-summer N, SW, SC, SE, HA
Gladiola Gladiolus spp. Early summer N, SW, SC, SE, HA

*Hardy summer bulbs can be planted permanently into the garden, tender bulbs must be handled like annuals with the bulbs being harvested and stored indoors during the winter months.

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.

Caladiums

Caladiums provide great summer foliage color


Fall Flowering Bulbs

A few bulbs bloom during the fall season. Those listed below are hardy in Idaho and include:

Common Name
Scientific Name
Relative Bloom Time
Regional Adaptation
Colchicum Colchicum autumnalis Late Fall N, SW, SC
Crocus (late types) Crocus spp. Late Fall N, SW, SC, SE
Hardy Cyclamen Cyclamen spp. Mid Fall N, SW, SC, SE
Lily Lillium spp. Mid Fall N, 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.

Crocus

Some Crocus species bloom in the fall


The International Bulb Society has constructed a picture gallery that includes most of the worlds bulb propagated plants.

A fact sheet from North Carolina State University provides assistance with selection of bulb plants.

 August 17, 2012