In anticipation of spring and your spring planting plans (and as I am sorting through mountains of photos, film footage, and text for the butterfly gardening show), I am planning a little series here on the blog. The focus is all about sharing information and photos about individual plant species that provide sustenance and shelter for the pollinators that grace our gardens.
Two of our very favorite native plant species for attracting Ruby-throated Hummingbirds are the blossoms of the northern catalpa tree (Catalpa speciosa) and trumpet creeper (Campsis radicans), both of which belong to the Bignonia family. Catalpa trees bear white flowers with violet nectar guides and, despite their color differences, Catalpa blossoms and the red-orange flowers of trumpet creeper reveal several similarities, The reproductive structures are positioned inside at the top lip of the opening, surrounded by five asymmetrically shaped petals fused together. As the hummingbird pokes its head deep inside the trumpet-shaped blossom to extract nectar, the pollen-bearing sticky stamens and pistils attach to its forehead and transfer pollen from one blossom to the next.
Nectar volume influences the blossoms’ attractiveness to the Ruby-throated Hummingbird. The small florets of plants such as those of butterfly bushes and zinnias offer nectar, though they require many visits to make it worthwhile. Our native Campsis radicans produces one of the highest known volumes of floral nectar per flower. Hummingbird fledglings quickly learn from their mothers the blossoms that contain the most nectar.
Campsis radicans is found growing throughout much of the eastern half of the country. Unable to support itself vertically, it trails along the ground until it reaches a tree. Tiny aerial rootlets are formed to adhere itself to the surface of the tree to then allow it to climb skyward towards the sunlight. Unlike vines such as Chinese wisteria and bittersweet, which gird and then strangle a tree, trumpet creeper clings tightly. Campsis radicans is a very fast growing and top-heavy vine. It is unsuitable for anything but the strongest structure. As it blooms on the current year’s growth, it can be grown along a solid fence and cut back very vigorously in early spring.
For the intimate garden or garden room, where a less rampant (but no less hardy) grower is a more suitable choice, there are several hybrids of C. radicans with flowers that are as equally attractive to the hummingbirds. ‘Madame Galen’ (Campsis radicans x tagliabuana) flowers in lovely shades of apricot-orange. The newer cultivar ‘Indian Summer’ is described with the less persistent and dense growth characteristics similar to that of ‘Madame Galen’ and beautiful blossoms of apricot-orange with a deeper red eye.
The extended period of florescence of C. radicans corresponds to the span of time in which ruby-throated hummingbirds are living in their northern range. Like Chinese wisteria, trumpet creeper can take six years or more to flower from seed. Plant the largest specimen one’s budget will allow.
|Kingdom||Plantae – Plants|
|Subkingdom||Tracheobionta – Vascular plants|
|Superdivision||Spermatophyta – Seed plants|
|Division||Magnoliophyta – Flowering plants|
|Class||Magnoliopsida – Dicotyledons|
|Family||Bignoniaceae – Trumpet-creeper family|
|Genus||Campsis Lour. – campsis|