Wildly Successful: Crocosmia x crocosmiiflora

Crocosmia x crocosmiiflora. Photographs by David Goldberg

Crocosmia x crocosmiiflora. Photographs by David Goldberg

The vibrant two-toned orange flowers of the plant we call montbretia brighten many a Northern California park or garden in summer. It is a survivor from the late nineteenth and early twentieth centuries, when gardeners in Europe and America were wild for the new Crocosmia cultivars that were being bred every year. Many of these had larger flowers or more interesting coloration, but our common montbretia is the oldest of them and one of the sturdiest.

All crocosmias are native to Southern Africa, mainly to the eastern, wet-summer regions. Crocosmia aurea, a denizen of woods and stream banks from the Eastern Cape through Tanzania, was the first to reach Europe, in 1847. Arriving about twenty years later was C. pottsii, a species with a narrower range but a similar habitat. In 1880, Victor Lemoine, a French nurseryman, crossed these two species to create our montbretia.

Montbretias flower reliably for about two months, usually from early June into August, and all are in bloom around the Fourth of July, earning them the local common name of “firecrackers.” For long-lasting cut flowers, cut stems when the lowest blossoms have just opened, but leave plenty in the garden to feed the hummingbirds that will visit often.

While montbretias and other Crocosmia cultivars may survive a relatively dry summer, they will perform better with water every couple of weeks. When leaves die back in late summer, cut them down to an inch or two above ground, using sharp pruning shears. Although the plants are dormant until their leaves sprout in spring, they tolerate our winter rains. Winter mulch is advisable where frost is common, and summer mulch is a good idea where summers are hot.

Divide crowded clumps in early spring, no more often than once in three years, since division reduces flowering a bit in the next season. Crocosmia corms multiply by forming cormlets at the end of short runners. When dividing the plants, leave each group of cormlets attached to the parent corm, as it remains alive and provides some nutrition to the developing cormlets for at least the next year. Plant crocosmia corms two to three inches deep and six to eight inches apart in well-drained soil that has been amended with some organic matter. Because montbretia is a hybrid between two species, it may set few seeds, and those that do form may not grow. In any case, reproduction by cormlets is so successful that most gardeners are glad not to have seedlings as well.

Gardeners often do not remember planting montbretia in their gardens, and it is quite possible that they introduced the plant by accidentally bringing corms with the soil on a gift plant. Once established, a clump is long-lived and will steadily increase in size, but if the soil near the edges of the clump is cultivated lightly each summer, and if any adjacent lawn is mowed regularly, the plants will not spread rampantly.

To remove montbretias from the garden, dig out all of the corms and cormlets and pull the small gladiolus-like plants that sprout in subsequent springs from any pieces left behind. Montbretia has naturalized widely in England, as well as in Western Europe, Hawaii, and Australia. In California, it naturalizes primarily in areas with disturbed soil, such as roadsides, rather than in undisturbed habitats, so it is not among the worst of wildland weeds; it is important, however, not to discard into wild areas any soil containing corms or cormlets.

A cottage garden dominated by a clump of Crocosmia x crocosmiiflora

A cottage garden dominated by a clump of Crocosmia x crocosmiiflora

Varieties and Similar Species

Of the hundreds of Crocosmia cultivars created by the 1920s, three-quarters were lost by the end of World War II, in part due to a fall from fashion and in part due to the upheavals of war. Many cultivars were lost in Great Britain through the “Dig for Victory” campaign, in which flower gardens were dug up to grow vegetables.

Some older varieties still available are: ‘Solfatare’ (sometimes misspelled as ‘Solfaterre’; (bred by Lemoine; smoky brown leaves, deep yellow flowers, two feet tall, late summer), ‘George Davison’ (green leaves, orange yellow flowers), and ‘Emily McKenzie’ (two and one-third inch flowers, yellow with red markings). In the latter part of the twentieth century, English plant breeder Alan Bloom created a number of new cultivars. One important parent of his introductions is Crocosmia masoniorum, a species that holds its flowers upright on the stems. This trait is evident in the popular cultivar, ‘Lucifer’ (scarlet red, three feet tall).

The genus name Crocosmia (krow-koz’-mee-uh) derives from the Greek words krokos (saffron) and osmea (a smell), chosen because, when the botanist who named it soaked the dried flowers of C. aurea in hot water, he found the water turned yellow and smelled like saffron crocus. While the plant is sometimes used as a dye source, no one seems to have picked up the idea of using it as a saffron substitute.

But why is it called montbretia? There are two parts to the answer. First, when Lemoine made his initial cross, Crocosmia pottsii was classified as Montbretia pottsii, so he named the hybrid Montbretia x crocosmiaeflora (mont-bree’-she-uh ex krow-koz-mee-aye-flor’-uh). When the classification of Crocosmia and the related Tritonia and Gladiolus was finally settled, the genus Montbretia disappeared, all of its members having been transferred to different genera. Our common garden plant became Crocosmia x crocosmiiflora, but gardeners disliked this tongue twister, so opted for just plain montbretia. (The name is now sometimes also used for other Crocosmia species and hybrids.)

The genus name Montbretia honored Antoine Francois Cocquebert de Montbret, a promising young French botanist who sailed to Egypt with Napolean’s army in 1798. He was to serve as a librarian but fell ill and died in Cairo in 1801, when he was only twenty. In 1803, a French botanist, who was his friend, created the now obsolete genus in his honor.