Hardy Bulbs for Wisconsin Gardens [Updated]

With our abbreviated growing season here in Wisconsin, bulbs are invaluable for extending the bloom season. Take some time this autumn to plant bulbs to reward yourself with years of early season blossoms.

How to Plant Bulbs in Wisconsin FAQ

• Where to plant bulbs? Plant in loamy, well drained soil. With few exceptions, bulbs will rot in wet soils.
• When to plant: Hardy spring blooming bulbs must be planted in the fall. The ideal time for planting is following “Indian Summer”, when autumn temperatures really set in. In southeastern Wisconsin this is usually the month of October.
• Do I need to fertilize? Adding fertilizer when you plant will provide resources to the bulb to increase its perenniality. Our organic, slow-release Espoma Bulb-Tone fertilizer includes beneficial mycorrhiza that greatly increases the plant’s ability to utilize soil nutrients.
• How deep? 2-3 times the height of the bulb
• How far apart? Bulbs are most effective when massed, so digging one large hole to plant a group of bulbs creates a nice show. Leave at least a bulb’s width between each bulb.
• Should I cut my bulb plants down?
  Bulbs make excellent cut flowers, so cut as many blossoms as you like for floral bouquets. Once the flowers have faded you may cut the spent flowers off to encourage the plant to put its energy into underground growth rather than seed production (exceptions would be bulbs with attractive seed heads such as Alliums, or those that you want to allow to self-sow).
  
  Do not cut the fading foliage down as the plant needs the energy provided by the foliage to nourish the bulb for future years of bloom.

Bulbs are a seasonal item. Stock is typically available in early-to-mid September. They are available while supplies last.

Allium bulbs mixed into Native planting.

Siberian Squill bulbs naturalized.

Early Season Bulbs (“minor bulbs”)

You can add an entire season of interest to your garden with early season bulbs. Those dreary days of March & April can be spent enjoying abundant bloom rather than just waiting for the garden to wake up.

Bonus: these plants disappear into dormancy by the time your perennials emerge so there is no unsightly period of waiting for the foliage to mature.

Snowdrops

Galanthus

The very first flowers to emerge in early spring/late winter, Snowdrops often bloom surrounded by ice and snow. Delicate pendant white flowers accented with a touch of green. Height 6”.

Winter Aconite

Eranthus

Preceded only by the Snowdrops, these bright yellow buttercup-like flowers bring welcome color to the otherwise dormant garden. Height 3”-4”. Unlike other bulbs, these should be soaked in warm water for 24 hours before planting.

Crocus

The species crocus (“Tommy” and vernus crocus) tend to be less desirable to squirrels & chipmunks.

• Crocus vernus ‘Pickwick’ – Showy cup shaped flowers sport vivid purple & white stripes. Yellow anthers add contrasting color. Height 4”-5”
• Crocus tommasinianus ‘Ruby Giant’ – Sometimes called Snow Crocus because it blooms so early in the spring. Delicate reddish-purple flowers with white throat. Height 3”-4”

Glory of the Snow

Chionodoxa

True to their name, these beauties often bloom right through the snow. Deer & rabbit resistant.

• Chionodoxa ‘Blue Giant’ – Up facing sky blue star-like flowers with white centers. Height 3”-5”. Staff Favorite. ?
• Chionodoxa ‘Pink Giant’ – Palest pink star shaped flowers with white centers. Height 3”-5”.

Siberian Squill

Scilla siberica

True blue, down-facing flowers. An eager spreader, this little bulb will seed to create a carpet of blue. Height 4”-6”.

Dwarf Iris

Iris reticulata

A true miniature Iris with petite blue flowers in early spring. Height 4”-6”.

Mid-Season Bulbs

By late April/early May the early season “minor bulbs” will be disappearing into dormancy and the next season of bulb bloom will begin.

This group produce globe-like flowers in a tremendous range of sizes, with colors including purple, white and true blue. As members of the onion family, they are deer and rabbit resistant. The seed heads are decorative enough to leave standing after bloom (sometimes we even get silly and paint them different colors). Staff Favorite! ?

• ‘Ambassador’ – Dense purple flower heads up to 7” across, atop statuesque 48” stems. This one gets a lot of attention in our display gardens. Stunning!
• ‘Globemaster’ – Huge, dense purple globes up to 8” across. Height 36”.
• ‘Purple Sensation’ – Lilac-purple flowerheads, 4″ wide. Height 24”-32”. Naturalizes by seed if allowed to self sow.
• Christophii – An heirloom variety (Circa 1884) known as “Star of Persia”. Immense 8”-10” starry silvery-violet flowers. Height 18”-24”.
• ‘Mount Everest’ – Tightly compacted, 6″-wide, white globes accented with lime-green eyes. Height 36″.
• Caeruleum – Another heirloom variety (Circa 1830), this one was historically called “The Blue of the Heavens”. Small 1”-2” sky blue flowers on wiry stems. Plant in clusters for best effect. Height 15”-18”.
• ‘Gladiator’ –7” violet-purple flowers atop 36”-48” stems.
• Schubertii – Known as the “Fireworks Allium”, this one produces immense, airy, rosy-lilac flowers up to 12” across on short stems. Heirloom (circa 1896). Height 12”-15”.
• ‘Graceful’ – Graceful 3” white flowers, accented with lavender. Heirloom (circa 1857). Height 12”-15”.
• ‘Giganteum’ – The original Giant Allium, this one produces dense 6” purple globes atop 48”-60” stems.
• Sphaerocephalon – Known as the “Drumstick Allium”, this one is the latest to bloom and has a distinctly different look from the others. Raspberry-purple, 1” egg-shaped flowers in mid-summer. Especially effective when massed. Heirloom (circa 1550). Height 24”.

Camassia

A native of the Pacific Northwest, this is one of the few bulbs that will thrive in moist soil. Spires of flowers in early summer. Staff Favorite. ?

• Caerulea – Spikes of blue star-like flowers in early summer. Naturalizes if allowed to seed. Heirloom (circa 1853). Height 24”-30”.
• Alba – Creamy white star like flowers on 24”-30” stems in early summer.

Hyacinth

Intensely fragrant dense, stout flower clusters.

• ‘Delft Blue’ – Porcelain blue flowers. Height 12”.
• ‘Tequila Sunrise’ mix – A festive mix of yellow, orange and burgundy-purple. Height 10”-12”.

Grape Hyacinths

Muscari

A miniature version of Hyacinth, with grape-like flowers clusters.

• ‘Valerie Finnis’ – Powder blue flowers. Height 6”-8”. Staff Favorite. ?
• ‘Julia®’ – Blue flowers, edged in white. Height 6”-8”.

Summer Snowflake

Leucojum

Sometimes called Giant Snowdrops, this gracefully elegant plant produces clusters of lovely, pendant, cream-white flowers edged in green. Deer & rabbit resistant. Heirloom (circa 1594). Height 15”-18”. Staff Favorite. ?

Persian Lily

Fritillaria persica

Smoky plum colored, bell-shaped flowers combined with interesting silvery-green wavy foliage make this plant a real standout. Requires well drained soil. Heirloom (1585). Height 24”-30”.

Mediterranean Bells

Nectaroscordium/Allium siculum ssp. bulgaricum

This one is fun! Twisted, curly foliage emerges first, followed by tall stems bearing papery buds that open to candelabra-like clusters of pendant cream and burgundy flowers. More interesting than beautiful, but a favorite. Deer & rabbit resistant. Heirloom (circa 1870). Height 30”-36”.

Daffodils

Narcissus

With hundreds of varieties and types available, its difficult to know which daffodil to choose. We’ve tried to offer a selection of the major groups. All are deer & rabbit resistant and long lived.

• Trumpet Mix – Classic daffodil form. A single flower per stem, with a long central “trumpet”.
• Double Mix – One or more fully double flowers per stem.
• Butterfly Mix – The central cup is split, so that it resembles a butterfly.
• Pink Mix – Daffodils aren’t always yellow! This mix offers various shades of pink.
• Tete a Tete – A super popular dwarf early blooming daffodil. A favorite!

Check out Growing Paperwhite Narcissus Bulbs in the winter.

Tulips

A cut flower classic. Beautiful range of colors and forms. Unfortunately, hybrid tulips are a favorite of deer and tend to not as long lived as other hardy bulbs.

• Lily Flowering Mix – Elegant, chalice shaped flowers with pointed tips
• Parrot Flowering Mix – Striated colors and twisted, unusual flower form
• Double Mix – Fully double, peony-like flowers
• Single Late Mix – Single, late blooming flowers in a range of colors
• Triumph Mix – Mid Season, single flowering
• Darwin – Sometimes called “perennial tulips” because of their tendency to perform well for years in the garden.
  • Hakuun – White single
  • Parade – Red single
  • Design Impression – Pink single with variegated foliage
• Species Tulips – Reliably perennial and less likely to be eaten by deer & rabbits.
  • Tarda – Star shaped yellow & white up-facing flowers on very short 1”-2” stems. Staff Favorite! ?
  • Greigii ‘Little Red Riding Hood’ – Attractive bi-color foliage and single red flowers on short 6”-10” stems.

by Zannah Crowe