It’s now early fall and that means it’s time for Colchicum! Colchicum is a group of flowers also known as autumn crocuses, though they’re not related to the true crocus. Seventeen species and varieties of Colchicum grow in the Graham Bulb Garden. Flower colors range from white to magenta-violet, and include doubles and bicolors.
Colchicum blooms are a great way to brighten up the early autumn landscape. They’re best grown in a groundcover or as an underplanting for taller bulbs such as lilies (Lilium sp.). The spring foliage can be rather large and hosta-like, making them sometimes difficult to pair with smaller spring-blooming bulbs such as Scilla, but it makes them perfect for hiding bare stems of tall plants in the summer while providing a jolt of color to your beds just before everything goes to sleep for the fall.
In addition to the crocuses, dahlias and lilies are still bursting forth with color, like jewels in the September garden. The cooler temperatures help create richer colors in the dahlias, and longer-lasting blooms, while their large size provides a contrast with the dainty blooms more typical of fall bulbs. We’re still seeing the final blooms of Lilium speciosum ‘Uchida’ as well. This lily is notable for being the latest-blooming lily in our climate. These plants started blooming in early September and are still holding on. Due to their late blooming nature, these beauties must be planted in the spring in a well-drained but fertile area.
While these might be the last blooms of the season in the Bulb Garden, this certainly isn’t the end of interesting things happening in the Chicago Botanic Garden. Fall foliage color will be peaking soon, and winter holds its own interest in the colors of berries, dogwood stems, and the exfoliating bark of the birches against snow’s white blanket.
Spring is done and we’ve finally moved into summer bulb season! The annual beds have been replanted with sweeps of dahlias, cannas, caladium, and begonias to showcase these nonstop workhorses of the summer garden.
On the perennial side of things, we’re moving into lily season. The very first lilies to bloom are the martagon lilies (Lilium martagon) and their hybrids (such as Lilium martagon ‘Mrs. R.O. Backhouse’). Martagon lilies are terrific plants for the shade garden because they provide both structure and color at a time when little else is blooming in the shade. The leaves emerge in a layered whorl, giving the plants a pagoda-like structure. We’re also moving into Asiatic lily season with the first of those beginning to bloom in bold shades of pink, red, yellow, and orange.
In addition to the lilies, we’re also seeing some unusual bulbs such as Eremurus ‘Lemon Meringue’ in bloom. Eremurus have tall, bottle brush-like flowers that add an exotic flair to the garden. Smaller alliums such as Allium tanguticum ‘Balloon Bouquet’ and Allium senescens do not have the giant flower heads of their springtime relatives, but still provide a welcome change of pace from the more common flowers of summer.
The Chicago Botanic Garden’s plant breeder, Jim Ault, shows you how he hybridizes lilies in his backyard. You can learn more about lilies at the Wisconsin-Illinois Lily Society Show on July 10 and 11 at the Chicago Botanic Garden. Visit chicagobotanic.org/plantshows for more information.