Updated: Nov 2, 2021
Trumpet vines are numerous, and a few thrive here on the West Coast of the United States. Because of their exotic trumpet-shaped flowers and lush growth, they are quite popular for sub-tropical and tropical aesthetics. Thankfully, several can tolerate Northern California winters, and more seem to be acclimating to our changing climate. Campsis radicans is one of them, but unlike others, it will likely go deciduous in our coldest areas. Once the weather warms, it will spring back and bloom prolifically.
Common trumpet creeper is easy to grow, but there are some details to consider. The stems send out aerial roots that cling to surfaces, such as wood, bricks, stone or stucco. If this is desirable, then it is a good choice. If not, then problems will occur when trying to remove it from the surfaces. For example, limbs and roots will leave marks from the surfaces that they clung to, requiring damage repair. If left alone, which is certainly an option, it has the capability of clinging to areas that an owner might not appreciate, such as adjacent trees, house eaves, and even crawl into attics (see photo below). These situations will cause more damage, so please fully understand where the vine will be located.
An easier solution is to locate it on garden walls or freestanding pergolas to avoid traveling to unwanted places. Once the location is resolved, then maintenance should also be considered. Being a vigorous climber, keeping up with pruning will be essential, both during the growing season to keep it contained and over the winter to refine its form.
A quick comment about tropical gardens in Northern California. We still receive frosts, so it is up to designers to know the hardiness limits of the tropical species they specified. Fortunately, there are numerous plants and trees that lend themselves to tropical effects without too much concern about frost. For example, some palms are desert or Mediterranean species that not only look tropical but are drought and frost tolerant, such as our native Washingtonia filifera. Campsis radicans fits this bill with its tropical appearance yet drought tolerance and cold hardiness, even finding its way to the coldest parts of our country.
The final slide in this album is C. radicans trained as a standard. Who thinks this is a good idea? Apparently a number of people. When searching "Campsis radicans topiary," several photos come up of stunning tree formed specimens in full bloom. My immediate thought ponders the maintenance, as this vine is a fast grower. If someone is willing, then who am I to say?
Botanical Name: Campsis radicans
Campsis: Greek, kampe for bent (stamens)
Radicans: Having stems with aerial roots
Common Name: Common trumpet creeper
Family Name: Bignoniaceae
Origin: Eastern United States
Positioning: On structures
Garden Themes: Sub-tropical/tropical, pollinator, hummingbirds, cottage
Uses: On walls, arbors, fences, and other structures (with caution), ground cover (remember it is deciduous)
Type: Semi-evergreen to deciduous vine
Form: Upright, spreading
Size: 40' tall and wide
Outstanding Feature(s): Flower
Bark: Light brown, scaly
Stems: Light brown with aerial roots that cling to surfaces
Type: Odd pinnately compound
Shape: Elliptical, oblong (leaflets)
Color: Dark green turning yellow to yellow-green in fall
Surface: Smooth, glossy
Flower: Summer to Autumn. Large trumpet, brilliant orange in terminal clusters.
Fruit: Green legume pod turning brown then opening to reveal winged seeds
cultural requirements, tolerances & problems
Sunset Zones: 1-21
USDA Zones: 4-10
Light: Sun to part shade
WUCOLS SF Bay Area Hydro Zone: Low
Texture: Sand, loam, clay, well composted
Moisture Retention: Well-drained
pH: Highly acidic to highly alkaline
Tolerances: Deer, heat, drought, poor soil
Problems: Clinging nature of stems may become problematic damaging materials where attached. The heavy weight of the foliage may pull away from supportive structure (pruning recommended). Can be an aggressive requiring management. North Carolina State University notes a fire risk of extreme flammability. Low toxicity.
Branch Strength: N/A
Insects: None recorded as of this writing
Disease: None recorded as of this writing
citations & attributions
Bayton, R. (2019). The Royal Horticultural Society's the Gardener's Botanical: An Encyclopedia of Latin Plant Names. London: Mitchell Beazley.
Extension Gardener Plant Toolbox. "Campsis radicans." North Carolina State University, Raleigh. Accessed on August 21, 2021, from https://plants.ces.ncsu.edu/plants/campsis-radicans/.
Norris Brenzel, K. (Ed.). (2012). The New Sunset Western Garden Book. New York: Time Home Entertainment, Inc.
Plant Finder. "Campsis radicans." Missouri Botanical Garden, St. Louis. Accessed on August 21, 2021, from http://www.missouribotanicalgarden.org/PlantFinder/PlantFinderDetails.aspx?taxonid=277901.
Water Use Classification of Landscape Species. "WUCOLS IV Plant List." University of California, Division of Agriculture and Natural Resources, Davis. Accessed on July 27, 2021.
Flower detail: "Trumpet Vine - Campsis radicans, Woodbridge, Virginia" by Judy Gallagher is licensed under flickr.
All other photos by TELCS.