Trumpet Creeper (Campsis grandiflora): A Complete Guide

Campsis grandiflora, also known as Trumpet Creeper, is a climbing vine plant from the Bignoniaceae family and Campsis genus. It has a woody stem with peeling bark and a brown hue, using aerial roots to cling to supporting structures.

Its leaves are opposite, forming odd-pinnate compound leaves. Each leaf comprises 7-9 ovate to lanceolate leaflets, with 6-7 pairs of lateral veins, hairless surfaces, and coarse serrated edges.

The leaf axis is 4-13 cm long, and the leaflet stalks are 5-10 mm long. The plant bears loosely arranged short conical inflorescences at the apex, with an inflorescence axis length of 15-20 cm. The calyx is bell-shaped and 3 cm long.

The corolla has a bright red interior and an orange-yellow exterior, about 5 cm long with semicircular lobes. The stamens are attached near the base of the corolla tube.

The pistil is linear and about 3 cm long. The fruit is slender and pod-like, with a blunt tip, and each pod contains several seeds. It blooms from May to August.

It is found in China and Japan, and is cultivated in Vietnam, India, and Pakistan. It is robust and loves warmth, with a certain degree of cold resistance.

It prefers full sunlight but can also tolerate shade. It can grow normally in saline-alkali and poor soil, but prefers deep, fertile, well-drained, slightly acidic soil.

In addition to being ornamental, it can also be used medicinally. The flowers are used as a diuretic and can effectively treat injuries from falls or blows.

I. Morphological Features

Climbing vine; stem is woody with peeling bark and brown color, using aerial roots to climb on other objects.

Leaves are opposite, forming odd-pinnate compound leaves; each leaf has 7-9 ovate to lanceolate leaflets, with uneven sides, 3-6(-9) cm long and 1.5-3(-5) cm wide, with 6-7 pairs of lateral veins, hairless surfaces, and coarse serrated edges. The leaf axis is 4-13 cm long, and the leaflet stalks are 5-10 mm long.

Loosely arranged short conical inflorescences at the apex, with an inflorescence axis length of 15-20 cm. The calyx is bell-shaped, 3 cm long, split to the middle, with lanceolate lobes around 1.5 cm long.

The corolla has a bright red interior and an orange-yellow exterior, about 5 cm long with semicircular lobes. The stamens are attached near the base of the corolla tube, with linear and slender filaments 2-2.5 cm long, and yellow anthers attached in a cross shape.

The pistil is linear and about 3 cm long, with a flat, bifurcated stigma. The fruit is slender and pod-like, with a blunt tip, and each pod contains several flat seeds, most of which have thin wings.

II. Habitat and Distribution

Native to China and Japan, this plant is also cultivated in Vietnam, India, and Pakistan. The Morning Glory is robust and prefers warmth, but it also has a certain level of cold resistance.

It thrives in full sunlight, but it can also tolerate shade. It can grow normally in saline-alkali and barren soil, but it grows best in deep, fertile soil with good drainage, preferably slightly acidic.

III. Propagation Methods

Morning Glory is usually propagated by cutting, but it can also be propagated by sowing seeds, layering, and division.

Seed Propagation: Generally, seeds that mature in October each year are harvested and stored. In the spring, the stored seeds are cleaned and then soaked in water for 2-3 days before sowing. Germination usually occurs within 5-7 days.

Cutting Propagation: In northern China, vigorous branches of the year are usually cut into cuttings in November-December. Each cutting should be 10-15 cm long (usually with 3 nodes).

These are then stored in sand and inserted into nursery beds in March-April of the following year, where they easily develop new roots. In the south, hardwood cuttings can be taken in early spring, and softwood cuttings can be taken in summer.

After rooting, the cuttings are transplanted and can flower the following year.

Layering Propagation: Layering is even more successful because Morning Glory stems have many aerial roots, which can take root as soon as they touch the ground.

The branches are cut into small pieces, each about 10-15 cm long, and laid horizontally on the nursery bed. A thin layer of ripe yellow soil is lightly covered on top, and the cuttings are kept moist.

Generally, in 10-15 days, a root system 5-8 cm long can grow. Choose the right time to transplant into a plant.

Division Propagation: Division propagation is done by digging up and transplanting the root suckers that grow at the root. After transplantation, they can quickly survive.

IV. Cultivation Techniques

Pot Planting

Soil Selection: It is advisable to choose well-drained, breathable, neutral or slightly acidic sandy loam soil. Alternatively, you can mix equal amounts of leaf mould and vegetable garden topsoil to serve as potting soil.

Before planting, thoroughly mix the selected potting soil with well-rotted organic fertilizer. Opt for breathable clay pots or wooden barrels for your flower pots.

For trellis cultivation, you can either plant directly under the trellis or use container pots on the ground of the trellis. The number of pots can be determined based on the size of the trellis.

The cultivation container should be large to accommodate more potting soil, which will promote vigorous growth and rapid landscape formation after potting.

The plant thrives in light, tolerates semi-shade, but if it is always in a semi-shade location, the plant will not flourish, flowers will be few and pale. It is best to place it in a sunny spot and ensure good ventilation. Remember not to put it in a closed or poorly ventilated place.

Transplanting: Transplanting is generally carried out in March, but in southern China, it can also be done in the fall. When planting a new plant, apply well-rotted organic fertilizer in the hole as a base fertilizer, then water thoroughly after planting.

If it is a seedling, you can transplant during the rainy season, but remember to provide shade after planting to prevent scorching sun exposure, and keep the soil moist to promote the survival of the newly planted seedling.

The plant grows quickly and has a large body. If you are trellis planting, choose a sturdy and long-lasting support before planting. As the plant grows, you should gradually tie and guide it onto the support or let it climb and grow, forming a landscape effect as soon as possible.

Maintenance Management: The plant likes moist conditions, can tolerate drought, but fears flooding. During its growth period, water regularly to keep the potting soil moist, but avoid waterlogging.

From late autumn when the leaves begin to fall until the following spring when new buds appear, the potting soil should be slightly dry and somewhat moist.

After a period of cultivation, it is necessary to repot the plant and add a little bone meal or organic fertilizer to the potting soil. Apply a nitrogen-based fertilizer 10-15 days after budding to promote leaf growth.

From May onwards, reduce the application of nitrogen fertilizer and apply phosphorus and potassium fertilizer to promote flower bud differentiation and budding.

From June, spray 0.2% potassium dihydrogen phosphate fertilizer solution on the leaves every 7-10 days to help the plant overwinter. Do not fertilize in winter.

Pruning and Shaping: Pot-planted plants can be pruned once in winter, cutting off dead branches, overly dense branches, and branches affected by pests to increase internal ventilation and light, and maintain a beautiful tree shape.

After flowering, if you do not want to keep the seeds, remove the spent flowers promptly to avoid excessive nutrient consumption, which can impact the next flowering.

In early spring, depending on the situation, you can prune the overly long branches to encourage the growth of robust branches, reduce unnecessary nutrient consumption, and concentrate the nutrients on the flowering branches to produce more and larger flowers, enhancing its ornamental value.

Open-air Cultivation

Cultivating the Chinese trumpet vine is relatively easy to manage. Transplantation can be carried out in spring and autumn. The plants are usually transplanted with a clod of earth and should be supported by a stake after planting for its climbing growth.

After the seedlings are planted, weeds should be removed and the soil should be loosened 2-3 times during the growing period. In May of the first year, thin manure water is applied and then watered with clean water.

In June and July, calcium superphosphate or urea is applied to promote vigorous growth of branches and leaves. In autumn, trench compost or farmyard manure is applied. From the second year onwards, topdressing is carried out twice a year in June and July and in autumn.

The Chinese trumpet vine can be used for vertical greening and beautification of galleries, pergolas, walls, stone walls, dead trees, rockeries, and flower gates in gardens and wild cultivation.

To achieve the ornamental effect, regular pruning and timely trellising are necessary. For general ornamental purposes, pay attention to timely pruning of dead branches, pest-infested branches, dense branches, and shortening of overly long branches to promote the growth of more robust branches, reduce unnecessary nutrient consumption, and facilitate flowering.

If seeds are not kept after flowering, cut off the spent flowers in time to enhance the next flowering. As the vines grow in maintenance, they need to be guided or tied to pergolas, walls, flower galleries, etc., in stages to prevent them from growing creeping on the ground.

Depending on the environmental needs, some vines can be allowed to hang naturally, or be pulled up with iron wire for climbing growth, connecting up and down to look more elegant and beautiful.

Clean up the dead branches before the buds sprout each early spring and shorten the overly long branches to make the growth uniform and display excellent ornamental effects.

V. Disease and Pest Control

The Chinese trumpet vine is generally not prone to many diseases and pests, but timely prevention and control are necessary.

Diseases: Leaf spot disease and powdery mildew of the Chinese trumpet vine can cause defoliation and affect the ornamental effect. It can be sprayed with a 1500-fold solution of 50% carbendazim wettable powder or a 2000-fold solution of 25% rust ning wettable powder.

Pests: In the dry autumn and high temperature and high humidity seasons, the Chinese trumpet vine is susceptible to aphid infestation. Once it occurs, it can be sprayed with 6% imidacloprid emulsion oil or 2.5% cyhalothrin (enemy kills).

Mealybugs and scale insects can be sprayed on both sides of the leaves with an 800-1200-fold solution of 40% Le Guo emulsion oil.

VI. Primary Value

Aesthetic Appreciation

The twisting and twining trunk of morning glory is robust and primitive, adorned with bright, fragrant flowers that bloom for a long period. This makes it an excellent choice for indoor potted vine plants.

According to individual preferences, it can be shaped into various forms, making it a widely adored plant for both ground and pot cultivation.

Medicinal Use

Chemical Components

The morning glory flower contains flavonoids such as apigenin; phenylethanol glycosides such as syringin, also known as lilac glycosides, and ligustrin; triterpenoids such as betulinic acid, arbutin, 23-hydroxyarbutin, corosolic acid, hawthorn acid, and ajugol; sterols such as β-sitosterol and carrot sterols; volatile oils such as furfural and 5-methylfurfural.

The leaves of morning glory contain flavonoids such as hesperidin-7-O-α-L-rhamnoside (1→4)-rhamnoside, dihydroquercetin-3-O-α-L-rhamnose-5-O-β-D-glucoside; cyclic ether terpenoids such as wisterin, 5-hydroxywisterin, convolvuloside, convolvulol, 1-O-methyl convolvulol; triterpenoids such as betulinic acid, hederagenin, arbutin, and oleanolic acid.

Functional Effects

Morning glory flower has blood-activating, channel-passing, blood-cooling, and wind-expelling effects. Pharmacological research shows that morning glory flowers have antibacterial, antithrombotic, and antitumor effects.

Traditional Chinese medicine believes that morning glory flowers have blood-activating, channel-passing, blood-cooling, and wind-expelling effects.

Main Treatment

It is used to treat irregular menstruation, amenorrhea, postpartum breast swelling, erythema, skin itching, and acne. Modern clinical trials also use it to treat primary liver cancer, gastrointestinal polyps, lupus erythematosus, urticaria, and other diseases.

Pharmacological Effects

• Antibacterial: The decoction of morning glory flowers and leaves has been proven to inhibit Shigella flexneri and Salmonella typhi.
• Antithrombotic: The decoction of morning glory flowers has a significant antithrombotic effect; it can accelerate red blood cell electrophoresis, increase the rate of red blood cell electrophoresis, and keep red blood cells in a dispersed state. The triterpenoids and cyclic ether terpenoids contained in morning glory leaves have a certain inhibitory effect on platelet aggregation caused by collagen or adrenaline.
• Antitumor: The calyx extract of morning glory flowers has an inhibitory effect on protein kinase C extracted from bovine brain and has a certain cytotoxicity to skin cancer cells M4 in vitro.
• Effect on Vascular Smooth Muscle: The decoction of morning glory flowers has a relaxing effect on isolated porcine coronary arteries and can significantly inhibit their contraction.
• Effect on Uterine Smooth Muscle: The decoction of morning glory flowers can significantly inhibit the contraction of the uterus in non-pregnant mice, significantly reduce the contraction intensity, slow down the contraction frequency, and reduce the contraction activity. On the contrary, for the uterus of pregnant mice, the decoction of morning glory flowers can increase the contraction frequency and intensity, and enhance the contraction activity. The acetone:methanol (1:1) extract of morning glory flowers can also significantly enhance the contraction intensity of uterine muscle strips in pregnant mice.