Bulbs for Fall and Winter Interest

Just when the hostas, lilies, and other garden perennials are going to bed for the season, these bulbs are waking up. 

Arum

PHOTO: Closeup shot of the leaves of Arum italicum 'Jet Black Wonder'
Arum italicum ‘Jet Black Wonder’ has unique black spots and pink- tinged flowers.

Arum first emerge in the late fall. The broad, arrow-shaped leaves of Arum italicum are highly ornamental and sturdy—quickly perking up after hard freezes, providing a welcome spot of green in the winter garden. Throughout the winter, they remain green and full, providing a welcome burst of green in the winter garden. In the late spring, they send up creamy white flowers that resemble calla lilies (Zantedeschia sp).

Soon after flowering, the leaves die for the season, revealing showy, fruiting stalks of bright red, highly ornamental berries. While these berries are quite attractive, do be aware that they’re poisonous and should be planted where they won’t tempt any children or pets to eat them. If located in an ideal site, they will reseed and form a ground cover. There are dozens of varieties, each with its own unique leaf patterns.

PHOTO: Wilted Arum italicum in the Garden.
Arum italicum ‘Mamoratum’ after a cold snap.
PHOTO: Arum leaves look back to normal after warming up following a heavy frost.
This is the same Arum italicum pictured above after recovering from the frost.

Fall cyclamen

PHOTO: Cyclamen leaves emerge from the ground in spring.
Cyclamen hederifolium ssp. crassifolium

There are two primary types of cyclamen that are hardy in Chicagoland. These are the fall-blooming Cyclamen hederifolium and spring-blooming Cyclamen coum. The fall-blooming Cyclamen hederifolium have ivy-shaped leaves with stunning silver patterns and small, windswept-looking flowers. Cyclamen coum blooms in the late winter or early spring, and has heart-shaped leaves with silver patterns.

Both plants grow their leaves in the fall and carry them through the winter before going dormant in the spring. Their flowers range in color from pinks and lavenders to white. Cyclamen prefer a shady spot that doesn’t stay wet; otherwise the bulb will rot.

A great place to plant cyclamen is under deciduous trees, where the leaf canopy will protect the dormant tubers from excess rain. If sited properly, they will reseed and form a ground cover.

PHOTO: Cyclamen bloom through the leaf litter in Home Landscape Garden.
Fall cyclamen (Cyclamen hederifolium) blooming in Farwell Landscape Garden.

Fall allium

Among the latest-blooming bulbs are the often overlooked Allium thunbergii ‘Ozawa’ and A. thunbergii ‘Ozawa Alba’.  These relatives of onions form grassy clumps that look green and fresh all summer long and suddenly burst forth with small clusters of flowers resembling pink-and-purple lollipops in late October, often continuing until mid-November. (As of November 17, these were still going strong in the Farwell Landscape Garden, even after hard rain, several hard freezes, and a light snowfall!) Allium thunbergii prefers to be located in a sunny, well-drained location, where it will continue to grow and thrive for many years. These are great plants for a sunny rock garden, where they provide a welcome shot of color at the end of the season.

PHOTO: Purple fall onions blooming in the Garden.
Allium thunbergii ‘Ozawa’
PHOTO: White fall onions in bloom.
Allium thunbergii ‘Ozawa Alba’

©2013 Chicago Botanic Garden and my.chicagobotanic.org

Updated: Snow Drought!

There’s no doubt: it’s a snow drought, and records are falling like…well, like snowflakes should be falling.

  • Wednesday we broke the record number of days without a 1-inch snowfall (319).
  • Last weekend we broke the 1940 record of 313 straight days with less than 1 inch of snow on the ground.
  • Just 1.3 inches of snow (more near the lake) has fallen to date, compared to the norm of 11 inches.

It made us wonder: what does a snow drought mean for your garden?

To find out, we talked with Boyce Tankersley, our director of living plant documentation.

What Snow Drought Can Do to Your Garden

It’s easy to give snow drought the brush-off  (no shoveling! no scraping! no wet feet!), but it can damage your plants and affect the soil in your garden. The following can happen in a drought:

1. Moisture loss accelerates. “It’s the combination of no snow cover plus cold winter wind that does the damage,” Tankersley explains. “When there’s no snow, plants act like a wick in the soil, so the wind not only dries out the trees and shrubs, but also the soil they’re planted in.”  

2. Soil compacts. In a normal year in the Chicago area, it rains in November, so the moist ground freezes as temperatures drop. Ice crystals form in the soil. As winter progresses, snow piles up, preventing wind from reaching the frozen moisture in the ground. With spring thaws, ground ice melts, creating air pockets and naturally looser soil. In short, Tankersley says, “winter is good for gardens.” Without that rain/freeze/thaw cycle, air spaces can’t form in the soil, so it collapses and compacts, requiring mechanical tilling to loosen it up again.

3. Plants get stressed beyond capacity. In 2012, plants endured an early spring with a late frost, followed by summer and fall drought, and now, snow drought. There’s a real risk of winterkill—the term used when plants succumb to winter conditions. “Check trees and shrubs for buds in early May,” Tankersley suggests, “especially nonnatives like Magnolia soulangeana, which is particularly susceptible to winterkill.” Even well-established, old trees can succumb—forever changing yards and neighborhoods.

What You Can Do to Help Your Garden

On mild days when temperatures are above freezing, Tankersley’s strategies for home gardeners include the following:

mulched tree

1. Mulch. Like a thick blanket, mulch holds in moisture and creates a layer of insulation for soil. Tankersley’s choice in his own yard? Oak leaf mulch. Why? “The leaves decay slowly, so they release nutrients into the soil over time.” Other options: chopped up plant material from your yard (non-diseased, please), or scattered straw. 

2. Add native plants in spring. Natives are already naturally adapted to outside-of-the-bell-curve extremes, with some sporting roots 15 to 20 feet deep. Compare that to a typical landscape plant with roots just 6 inches deep.


©2013 Chicago Botanic Garden and my.chicagobotanic.org

A Way to Brighten Your Birch Trees

As you walk near McGinley Pavilion this winter, you may notice that the white stems of the birch trees are especially clean and bright. That’s thanks to six Chicago Botanic Garden volunteers who rolled up their sleeves and gently scrubbed the lower limbs of 30 whitespire birch trees to reveal their brilliant stems. While it’s not necessary for the health of the trees, the task does make the trees more beautiful — and luckily, it is very easy to do at home. Read more here and watch a video on how to do clean your trees.