Mention the word, bulbs, and most associate it with spring and summer blooming affairs. Lesser known, but nonetheless delightful, are the fall flowering colchicums and autumn crocuses. Blooming in shades of pinks and purples, these bulbs, corms actually, combine well with pastel mums and asters as well as many late blooming, cold tolerant annuals. One of my favorite combinations is the double flowering, mauve-colored ‘Waterlily’ colchicum surrounded by white sweet alyssum. Stemless flowers arise seemingly from nowhere adding an element of surprise to the fall garden.

 Colchicums, sometimes referred to as meadow saffron or autumn crocuses, which they do resemble, are not related to true crocuses and are members of the Colchicaceae family. The large corms are poisonous and as such won’t be bothered by pesky rodents. A poisonous compound, colchicine, is derived from the plant and used on tissue cultures in plant breeding laboratories to produce new plant varieties by genetically altering the chromosomes. According to Dr. Mark Brand, University of Connecticut Plant Science Professor, “it is still used regularly in plant breeding to double chromosomes and make tetraploids.”

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Colchicum autumnale By Chromolithograph by Portail after Auguste Faguet – Dictionnaire de botanique by Henri Ernest Baillon and others, volume 3. Public Domain, https://commons.wikimedia.org/w/index.php?curid=3493546

Only a few of the 45 species of colchicum plus some hybrids are hardy here. Common autumn crocus (Colchicum autumnale) is most often found in garden centers and catalogs. It sports rosy-pink flowers up to 4 inches across usually in early October. There is also a single white flowering form, a double pink and a double white. Two inch wide leaves arise in the spring and die down by midsummer.

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Colchicum buds. Photo by dmp.

The showy autumn crocus (Colchicum speciosum) produces larger and showier flowers in the fall but also larger, coarser leaves in spring. Crimson purple, cup-shaped chalices may rise almost a foot above ground if well grown. It is said to multiply rather quickly so would be a good candidate for naturalizing. This species, too, has a white flowering form. 

Most enchanting are the hybrids made from crosses between these two species. Best known are ‘Waterlily’ with its striking bright pink, double flowers, amethyst-violet ‘Lilac Wonder’, and ‘The Giant’ with great violet flowers ending in a white base.

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Colchicum ‘The Giant’. Photo by dmp.

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Colchicum ‘Waterlily’ Photo by dmp.

As with spring flowering bulbs, the ripening colchicum foliage in early summer may look rather untidy. It can be hidden to some extent by planting the colchicums in groundcovers, under shrubs or amid not terribly aggressive perennials. Annuals can also be used to distract the eye from the yellowing foliage. Select annuals whose colors will blend well with the pastel pink and purple fall flowers.

colchicum foliage from MO Botanical Garden

Colchicum foliage. Photo by Missouri Botanical Garden

Corms should be planted as soon as they arrive, 3 to 4 inches deep. If they begin to bloom before you get them into the ground, don’t worry. It won’t hurt them but do get them planted so roots can begin developing.

True crocuses are members of the iris family. Most are grown for their early spring blossoms but several species flower in the fall making for a delightful accent during these early autumn days.

Fall crocuses are a little harder to come by locally than the colchicums and may need to be ordered from a catalog. All produce thin, grass-like foliage in the spring and should be planted 2 to 3 inches deep.

Most vibrant but easy to grow is the rosy lavender Crocus kotschyanus. Smaller flowering C. speciosus produces blooms in a rich, violet blue. The clear, lilac blue cups of C. pulchellus sport yellow throats at their base. A rarer white fall flowering crocus can also be found.

Crocus_speciosus_Artabir_jpg by Jane McGary www.pacificbulbsociety.org 1

Crocus speciosus ‘Artabir’ by Jane McGary from http://www.pacificbulbsociety.org

These corms may be tempting to mice, chipmunks and squirrels so plant in hardware cages or lay hardware cloth or chicken wire over the ground in which they are planted if you suspect a problem with these pests.

For something a bit out of the ordinary, colchicums and fall crocuses may be just the touch of excitement your fall garden needs.

Dawn P.