Thursday, July 10, 2014

Should you plant Crocosmia as a hummingbird flower?‏

Occasionally you have the opportunity to get a new flower for your garden and you wonder if it will provide nectar for your hummingbirds.  We discovered a beautiful red tubular flower from S Africa called crocosmia in a friend's garden and planted some in our VA garden.  It seemed ideal for hummingbirds and they do visit it, but less often than they search the flowers of nearby native coral honeysuckle.  A closer inspection of the flower reveals why it may not be ideal for hummingbirds.

The crocosmia flower is curved, possibly in a co-evolutionary development with the curved bill shape of sunbirds that feed on its nectar.   Sunbirds are convergent on hummingbirds but not closely related to them  ( ).  A flower in our FL gardens from S Africa, the Cape honeysuckle, is similarly strongly curved and defeats the attempts of our N American birds to drink nectar from the corolla tube.  Instead our birds, such as orchard orioles, and some bees have learned to bite through the base of the flower and steal the nectar.

The bill of our only eastern N American hummingbird is only very slightly curved and thus better adapted for relatively straight red tubular flowers from eastern N America such as coral honeysuckle and cardinal flower.
So when you are shopping for flowers to plant to feed your yard hummingbirds, carefully consider the shape as well as color to determine whether they are likely to be suitable.  In this case, native species are far more likely to be acceptable since they have evolved in concert with the native hummingbirds.  But if an exotic flower is red, has a relatively straight corolla tube of the proper length , and delivers sufficient nectar of high sugar concentration, it may be a better way to feed hummingbirds than by artificial sugar water.

Bill Dunson 

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