American trumpet vine

In our gardens the Trumpet vine looks like an exotic plant with its large calyx. Nevertheless, it is hardy and looks particularly attractive midsummer.

Jan 18, 2021 08:36 pm
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Growth type
  • Climber
Growth height (from)
from 800 cm to 1000 cm
Growth characteristics
  • Sling shoots
  • Adhesive roots
Flower color
  • yellow
  • orange
  • red
Flowering time (month)
  • July to September
Flower shape
  • tubular
  • Trumpets
Flower characteristics
  • unfilled
Leaf color
  • green
page format
  • feathered
Sheet properties
  • Autumn coloring
Fruit color
  • brown
Fruit shape
  • Capsule
Fruit characteristics
  • unimpressive
Light
  • sunny
Soil type
  • gravelly to loamy
Soil Moisture
  • moderately dry to fresh
ph value
  • alkaline to weakly acidic
Lime compatibility
  • lime-tolerant
Nutrient requirements
  • nutrient-rich
Humus
  • rich in humus
Decorative or utility value
  • Flower Decoration
  • Leaf ornaments
  • Nectar or pollen plant
Winter Hardness
  • conditionally hardy
Climate zones according to USDA
  • 6
Use
  • Climbing aids
  • Wall greening
Garden style
  • Flower garden
  • patio
  • Mediterranean garden
  • Rose Garden
Origin

As the full species name suggests, the Trumpet vine (Campsis radicans) is a native of southern North America. It grows there in swamps and riverside woodlands along larger rivers. The Trumpet vine is also known under the species name climbing trumpet and gives the climbing trumpet plants (Bignoniaceae) its family name. Incidentally, this also includes the non-climbing Trumpet tree (Catalpa bignonioides)..

Growth

The Trumpet vine is a fast-growing climbing shrub that anchors itself with the help of slightly looping shoots. In addition, like ivy, it forms adhesive roots and can therefore do without a climbing aid. It can reach heights of up to 32.8 feet in favorable locations, but it usually reaches only 16.4 feet. The bark of the older shoots is light gray to ocher yellow with conspicuous longitudinal furrows, the younger ones are green to gray-olive in color.

Leaves

The leaves of the Trumpet vine are deciduous, arranged opposite each other and pinnate. They can be up to 9.84 inches long, have a fresh green color and consist of nine to eleven leaflets. In the autumn before the leaves fall, they turn bright yellow.

Blossoms

The orange-colored bisexual single flowers appear from July to September and are 1.96 to 2.75 inches long. They have an elongated tubular shape and are arched like a trumpet at the end. The funnels are colored yellow on the inside and have a scarlet colored outer edge. The flowers form a cluster of 20 specimen at the ends of the new shoots. They gradually open up over a longer period of time and appear exotic with their bright color and unusual shape. They are primarily pollinated by butterflies. In case of freshly planted Trumpet vine, however, you often have to wait four to five years for the first bloom.

‘Mme Galen’
“Mme Galen” is a hybrid cultivar of the Trumpet vine, having particularly large flowers
Fruit

The seeds lie in narrow, 2.75 to 3.93 inch long capsules, which spring open in two flaps when ripe. In favorable locations, trumpet vines will sow themselves.

Location and Soil

Trumpet vines need a sunny, warm place, sheltered from wind, with a shaded root area.

The climbing shrubs are not demanding if they are on the ground. They are very pH tolerant and prefer moderately dry to fresh, loose and nutrient-rich garden soil.

Planting and Care

Like all warmth-loving trees, you should plant the Trumpet vine preferably in spring. Since the plants are sold with pot balls, they can even be planted in the middle of the gardening season and watered well. It is important, however, that they are reasonably well rooted by winter. When planting, loosen the soil thoroughly and ensure good drainage. If the subsoil is too wet, add construction sand. The wild species Campsis radicans in particular tends to form runners on loose soils. If it becomes bothersome, you can limit the rooting zone using rhizome barrier.

For larger specimens, reach out for your watering cans, if the summer dryness persists. However, all Trumpet vines like it if you add compost in the spring to provide nutrients. To keep the base of the plant well-covered, you can plant hostas or other large-leaved perennials with tolerant roots in the rooting zone.

Pruning

Trumpet vines only bloom at the ends of the new shoot. Therefore, by pruning in the spring, the blossoming of these climbing shrubs improves significantly. To do this, simply shorten the flowering shoots from the previous year to two bud pairs between the end of February and mid-March. These sprout again vigorously during the season and then bear particularly large flowers in summer.

Winter protection

It makes sense to provide winter protection to freshly planted specimen in the first few years. Cover the soil in the rooting zone with a thick layer of fall foliage and a layer of fir twigs. The shrub base is also protected from dry winds with fir branches.

Where to plant

Trumpet vines are ideal for greening Pergolas, courtyards, rose arches and trellises of all kinds. With their eye-catching flowers, they fit well into Mediterranean-style gardens, and can be combined with flowering tub plants and evergreen and flowering garden shrubs. For example, combinations with blue-flowering shrubs such as the Russian sage (Perovskia) and the “Heavenly Blue” beard flower Bluebeard (Caryopteris) are eye-catching. With color coordinated shrubs and climbing roses and the late-blooming varieties of Italian clematis(Clematis viticella), the plants also form a colorful ensemble.

Trumpet vines can also be grown in larger pots because they can be kept quite compact with regular pruning. However, they should then be placed in the cold greenhouse so that the pot does not freeze through.

Varieties

“Flamenco”: The variety is larger and bears more flowers than the wild species. The edges of the calyxes are colored light salmon pink.

“Flava”: Its flowers are yellow to yellow-orange on the outside. The inside of the calyx has a base color of orange with red vertical stripes.

Yellow Trumpet vines (Campsis radicans “Flava”)
Yellow Trumpet vines (Campsis radicans “Flava”)

“Madame Galen” (Campsis x tagliabuana): This is a hybrid of Campsis radicans and Campsis grandiflora. It forms very large flower trumpets with a diameter of up to 2.36 inches. The corolla tubes are colored orange on the outside and carmine-red to pink-red on the inside. With a height of up to 26.24 feet, it remains slightly smaller than the wild varieties.

Propagation

The easiest way to propagate the Trumpet vine and its varieties is by using its cuttings. In fall or spring you simply insert a well wooded annual shoot in the soil. During the season it forms roots and new shoots at the leaf nodes. You can separate these after a year. As young plants, continue to cultivate them in pots to protect them from frost, or transplant them to the intended location in spring. If your plant has runners, you can simply cut them off and transplant them in spring. Seedlings created by self-sowing are not recommended for further cultivation, as they take years to bloom and then tend to bloom less.

Diseases and Pests

Trumpet vines are rarely susceptible to diseases and pests. Occasionally there can be aphids- and infestation, however, neither is life-threatening for the plants. More problematic is the which can occur in rare cases, especially on unfavorable, very moist soils. It is incurable, but with a bit of luck you can prevent the infection from progressing if you transplant the trumpet vine to a convenient location as soon as possible.