fragrance isn’t overpowering, but it
is immediately and unmistakably identifiable.
Family: Compositae (Daisy family)
plants are invited into our gardens because they have attributes
startling enough to get our attention.
Then we find that once they are introduced into our landscape,
they are just too startling—too dramatic, too fragrant, too
colorful—to cohabit nicely with our other favorites. They may
simply overwhelm their neighbors, or they may turn downright
nasty and try to take all the space for themselves. I’ve had
this experience with night-blooming jasmine (who spilled all
that heavy cologne in the yard?!), with love-lies-bleeding
(way too dramatic for its companions), and with Houttuynia
cordata (how did it grow under that sidewalk overnight?).
Others might have similar memories of bamboo, of snow-in-summer
(great name and greater tendency to choke out everything around
it) or of Bishop’s weed. So I’ve learned to be cautious when
confronted with any plant that has the power to startle with
color, growth habit, or fragrance.
One startling perennial well worth bringing home
from the nursery or plant sale, however, is Cosmos atrosanguineus,
commonly and quite affectionately known as the chocolate cosmos.
This is a tuberous-rooted perennial, although of course it’s
a cousin to the annual C. bipinnatus that is a much-loved
staple in many of our summer gardens. Members of the daisy
family, all 26 or so species of the Cosmos genus are native
to Mexico and the southwestern United States.
C. atrosanguineus smells
like chocolate. Its fragrance isn’t overpowering, but it is immediately and
unmistakably identifiable. The color of its daisy-like, single
blossoms is as rich as my favorite sweet, too; but rather than
being “chocolate brown,” it is more of an oxblood red, neither
too orange nor too purple. It is a well-behaved plant with
an open form, growing to perhaps 30 inches. Its foliage is
bright green and deeply lobed, not unlike that of its annual
cousin. C. atrosanguineus is a good choice for foreground
planting, where its fragrance is accessible. It is quite a
conversation piece. Gaura, Linaria, Achillea, and Coreopsis
are all fine companions, as is any plant with silver foliage.
The requirements of C. atrosanguineus are
similar to many other perennials in your garden: full sun,
regular but not excessive moisture, and soil amended with plenty
of organic material. It is not vulnerable to any specific pest
or disease. C. atrosanguineus will break dormancy relatively
late in the spring but will grow quickly and bear flowers from
June through September. Propagation is best done in very early
spring, by carefully dividing the tuberous roots before growth
course, there’s a drawback. C. atrosanguineus is
only half-hardy in our area, which means that to be absolutely
sure it will survive the winter, you must lift the tubers in
the fall as you would with your dahlias. Growing your chocolate
cosmos in a container and overwintering it in a sheltered garage
or shed is another option.
C. atrosanguineus was
chosen as the January selection because it is interesting
and attractive, but also
because while its blooms have the scent of chocolate, having
it around won’t add any calories at all! In fact, I like to
think that preparing my beds for C. atrosanguineus and
other favorite perennials will reverse the effects of all that
real chocolate that gets nibbled each holiday season.
Happy New Year!