A yellow trumpet vine, Campsis radicans, is a species of perennial vine in the genus Campsis, which is part of the Bignoniaceae, or trumpet creeper, family. This vine is native to the southern U.S., but some cultivars will grow as far north as southern Canada. The vine makes an excellent fence or trellis covering. It is resistant to most common plant diseases and pests and is very easy to care for.
The yellow trumpet vine is also know as trumpet creeper, cow itch vine, and hummingbird vine. It grows in U.S. Department of Agriculture Hardiness Zones 4-10. This means that the lowest temperature the yellow trumpet vine can tolerate is -30° Fahrenheit (-34.4° Celsius).
It grows best in full sun, but will tolerate a bit of shade. Experts report that this plant thrives in poor soil and does not need fertilizer. Loam, sandy or clay soil should be well-drained and have a pH level between 4.6-9.0, which is highly acidic to strongly alkaline. Yellow trumpet vine has average water needs, but does not like soggy or muddy soil. It can tolerate some drought.
Gardeners can expect this vine to grow up to 30 feet (9 m) tall, with a spread of about 6 to 8 feet (1.8-2.4 m). For the first five years, yellow trumpet vine will grow only foliage. Once the plant matures, sometime between 5-10 years after germination, it will produce beautiful yellow, trumpet-shaped flowers that are approximately 2 inches (5.08 cm) across and 3 inches (7.62 cm) long. The yellow trumpet vine blooms from the middle of summer until the early fall. New foliage is emerald green and turns dark green and glossy as the plant matures.
Gardeners use yellow trumpet vine as ground cover or to cover unsightly fences, among others. In some areas, it may be considered invasive. After the first two or three years, the vine needs very good support to reach its full height. Bees and hummingbirds are attracted to gardens with trumpet vine.
Seeds can be sewn directly into the ground in the fall. Trumpet vine can also be propagated from softwood or hardwood cuttings, or by dividing the rhizomes. The best time to do this is in the fall or spring.
This is a low-maintenance plant that need not be pampered. It should be cut back to the ground at the end of each season. Some people have allergic skin reactions, so gloves are recommended when handling any part of the plant. Yellow trumpet vine may occasionally get a case of powdery mildew, but other than this, it is resistant to most diseases. Any pests can be handled with an insecticidal soap.