With its trumpet-shaped, lush flowers, the trumpet vine (Campsis radicans) is a decorative vine ornament. Its winter hardiness makes it a recommended alternative to the tropical angel’s trumpet (Brugmansia).
The trumpet vine is also commonly known as hummingbird vine, cow itch vine, and trumpet creeper.
Read on to find you what you should know about this American beauty and how best to cultivate it.
The American trumpet vine, botanically Campsis radicans, is more relevant to our local garden culture than the Chinese trumpet vine (Campsis grandiflora).
As its name suggests, it comes originally from America – more precisely, from the northern to central and eastern regions of the USA.
This also provides an essential cultivation-related distinguishing feature from the angel’s trumpet, with which the trumpet vine is often confused.
Unlike its confusion candidate originating from tropical regions, it is hardy, at least most varieties are.
The Chinese trumpet vine originates in eastern China and Japan and is not really hardy.
A hybrid of the American and Chinese trumpet vine, the Madame Galen (Campsis tagliabuana), is also often cultivated.
The trumpet vine grows as a woody climbing shrub with climbing tendrils that pull themselves up against walls or trellises with adhesive roots.
It is therefore a self-climber and does not necessarily need a climbing aid. Its growth is quite strong and depending on site conditions it can reach a height of up to 33 ft (10 m).
However, this is rather rare, usually, it remains at half this height. In container culture, it generally remains even smaller.
The Campsis tagliabuana grows as a liana-like shrub and grows as tall as the Campsis radicans.
Growth characteristics in a nutshell:
- Self-climbing, woody climbing shrub
- Strong growth
- Height about 16 to 33 ft (5 to 10 m)
The leaves of the trumpet vine, which grow up to 10 inches (25 cm) long, attach to the tendrils in opposite directions and present a pretty structural appearance with their unpaired pinnation.
They are bright, fresh green when young, and darken somewhat later. The individual leaves have a finely serrated margin and taper to a point at the end.
In the fall, the trumpet vine sheds its foliage after it turns bright yellow. In spring, it sprouts its foliage late, around mid-May.
The trumpet vine owes its name to its large, decorative flowers. They are indeed shaped like trumpets and are a stately sight with a length of up to 3 inches (7 cm).
Their tubular growth in front of the wide arching funnel at the end is very long. The flowers stand together in clusters of about twenty at the shoot ends.
The resulting large flower clusters stand out attractively against the green foliage with their intense coloration. Depending on the variety, the flowers are scarlet to sunny yellow.
On the stamens of the fairly accessible flower openings, the trumpet vine offers a rich nectar supply to beneficial and protective insects such as bees and bumblebees.
The trumpet vine flower in short:
- Long tubular shape with wide arched funnel opening
- Quite intense colors from scarlet to yellow
- Valuable food source for beneficial insects
Flowering Time for the Trumpet Vine
The trumpet vine blooms conspicuously late. Only in August and September does it develop its main bloom over several weeks and delight us with its colorful splendor until October.
In good weather conditions, the first flowers can also appear as early as June.
Unfortunately, you will have to be patient until you can enjoy the first bloom after planting. It takes about 4 to 5 years for the trumpet vine to become sufficiently established in its location for this feat.
- Flowering time for most varieties is between July and October
- For some varieties and in warm weather, it is even as early as June
- First flowering after planting only after about 4 to 5 years
What Location is Suitable for the Trumpet Vine?
The trumpet vine prefers a sunny, warm location. It should also be protected from rough winds.
It is also advantageous if its base is not exposed to full sunlight, unlike the upper part of the plant. But you can simply shade the root area with a ground covering plant, for example.
However, this should have a loose root system so that it does not constrict the shallow roots of the trumpet vine.
Trumpet vines do best in a generally milder, drier climate than in cool, wet areas.
The trumpet vine does not make high demands on the soil. It should be moderately nutritious, sufficiently moist, relatively loamy, but still permeable.
The pH value is of little interest to the trumpet vine, it copes with both acidic and alkaline soils.
The site requirements at a glance:
- Warm and sunny
- Protected from wind
- Soil area shady
- Soil moderately nutrient-rich, moist, permeable
- The pH value does not matter
Watering the Trumpet Vine
As a shallow rooter, the trumpet vine requires fairly attentive watering practices. Make sure that the root zone does not dry out too much and water regularly, especially during long dry periods in the summer.
Depending on the size of the plant, watering needs may also be higher. If you keep the trumpet vine in a tub, even more watering is of course necessary.
However, you should avoid waterlogging as much as possible. Always wait until the potting soil has dried thoroughly before watering again.
Fertilizing the Trumpet Vine Properly
Even at the time of planting, it is advisable to provide the trumpet vine with a permanent source of nutrition with mature compost in the excavated soil.
A fresh compost application every year in spring is also very beneficial for it. However, you should not go beyond this organic fertilizer application.
Above all, do not use liquid preparations containing nitrogen. They only stimulate growth to the detriment of flowering.
Pruning the Trumpet Vine
Since the trumpet vine generally shows vigorous growth, regular pruning is an essential part of its care.
To rejuvenate and increase vitality, it is best to first remove all dead, dried branches in the spring.
To promote lush flowering, you should also radically cut back all long side shoots on the main shoots so that the plant is encouraged to form new short shoots. Make sure that a few buds are retained in each case.
Trumpet vines also tolerate radical pruning well. You can even cut it back completely to the stem.
This usually results in vigorous new shoots and acts as an effective, basic rejuvenation treatment. However, you will probably have to do without a bloom the following year.
The pruning rules at a glance:
- Strongly growing trumpet vines should be regularly cut back
- Pruning is best done in spring
- Remove old tendrils, shorten long side shoots to promote flowering
- Rejuvenating radical pruning is well tolerated
Is the Trumpet Vine Winter Hardy?
The trumpet vines Campsis radicans and Campsis tagliabuana are both winter hardy. You can safely cultivate them permanently outdoors.
However, winter hardiness is not quite unlimited. The tolerance limit for both variants is about 1 °F (-17 °C), so in extreme winters cold damage is not impossible.
You should also protect especially freshly planted young trumpet vines from the cold during the first few years in winter with foliage and pine branches around the roots.
- Trumpet vines are hardy
- Protect especially young specimens from frost damage
The Trumpet Vine in a Pot
You can also cultivate trumpet vines well in a pot because regular pruning can keep them quite compact.
In a solitary position, however, a trellis framework is necessary to hold the climbing vines. You should compose the soil substrate rich in humus and implement drainage of coarse sand.
Watering and fertilizing with compost should be more gradual in the case of container culture.
Repotting the trumpet vine is only necessary when the pot becomes too narrow and the roots grow out of the drainage holes.
The trumpet vine in the pot is also somewhat more sensitive to frost. As a rule, however, it can be overwintered outside.
But if temperatures drop below 14 °F (-10 °C), it is better to put it inside or cover it well with garden fleece.
- Pot culture is well possible with regular pruning
- Install a climbing aid
- Use humus-rich substrate with sand drainage
- Regular watering and compost are necessary
- Repotting only when roots are tight
- Overwintering is better indoor
Propagating the Trumpet Vine
Recommended methods in trumpet vine propagation are mainly:
The best way to propagate trumpet vines is by the offsets method. To do this, place a woody shoot in a planter with soil in the spring and secure it with a metal hook.
Keep the substrate evenly moist. Rooting occurs gradually over the growing season.
You should not separate the offset plant from the mother plant until the following year and then continue to cultivate it, initially protected from frost.
Another method is to use runners. The trumpet vine prefers to form runners in loose soil. So here you can simply access and plant the severed seedlings in pots in the spring first.
Of course, it is also possible to propagate trumpet vines from your own seeds. However, you will then usually get specimens that are not particularly eager to bloom.
You can collect the seeds from the plant after the fruit ripens and let them dry. Soak them in water for about 6 hours before sowing. Sowing itself is possible all year round.
Germination in a pot with growing soil seeds needs quite a long time. It can take about 4 weeks until the germination happens.
Diseases and Pests
Fortunately, trumpet vines are very resistant to diseases and pests. Common but rather harmless aches and pains are powdery mildew and aphids.
You can recognize powdery mildew by the typical mealy coating on the leaves. However, the damage to the plant is moderate.
You do not need to use aggressive artificial means to control it. First, you should cut out the diseased parts of the plant.
A spray treatment with a milk-water mixture in the quantity ratio of 1:9 can also be helpful. If the infestation is severe or advanced, a fungicide may be necessary, though.
You can usually get a good handle on these parasites by rinsing them off with water. It also helps to use a decoction of nettles instead of water.
Why Does My Trumpet Vine Not Bloom?
On this subject, first of all, remember that a freshly planted trumpet vine needs 3 to 4 years to gather enough strength for a first flowering. So during this period, you do not need to hope for the splendor of colors.
If an established specimen fails to bloom, it may be due to the following reasons:
- Wrong location
- Lack of pruning
- Specimen grown from seed
The trumpet vine is a distinct sun and heat-loving plant. A location that is too dark, cold, and possibly draughty can spoil its flowering pleasure.
Young buds in particular can also freeze off in early spring under such conditions.
Lack of Pruning
Rejuvenation in the spring by pruning shoots is very important for good flowering.
This is because the trumpet vine only forms flowers at the fresh shoot ends. In the absence of pruning, new branches may not sprout at all.
Specimen Grown from Seed
A seedling propagated trumpet vine is generally rather reluctant to flower. Therefore, propagation from its own seeds is also not recommended.
However, some purchased specimens may well be grown from seed – this method is the most economical.
When buying, pay attention to a reputable origin and do not resort to the cheapest offer!
Madame Galen is one of the most common cultivars of the hybrid Campsis tagliabuana. This variety has a somewhat weaker growth habit than the wild Campsis radicans, but nevertheless also grows to an average height of 16 ft (5 m).
It should also be provided with climbing support. Its flowers have attractive coloring with yellowish-orange tubes and a scarlet funnel opening. They open starting in July and usually persist well into September.
The Campsis radicans Flava delights with its beautiful, sunny yellow flowers that appear between July and September. It is very fast-growing, making it especially suitable for quick wall plantings.
These climbing vines quickly become overhanging, so sturdy climbing support is indispensable. Like its original form, the Flava needs a sunny, warm location and likes to be shaded at the roots.
Compared to the wild form, this variety is somewhat smaller with an average height of growth of about 10 ft (3 m).
It also doesn’t tolerate quite as bone-chillingly cold temperatures – a maximum of 14 °F (-10 °C) is what you should expect of it.
This variety captivates above all by its particularly large and numerous flowers in rich orange-red. Also, the flowers generally appear somewhat earlier than those of the wild Campsis radicans.
It forms about 10 to 15 flowers per clump. In good conditions, Campsis radicans Flamenco can reach a height of 16 ft (10 m). It is very resistant to frost.
The variety Indian Summer also belongs to the hybrid species Campsis tagliabuana. It takes its name from the bright orange hue of its long flowers, which can appear as early as June and remain until October.
Indian Summer prefers a sunny to semi-shady location and reaches a moderate height of about 13 to 16 ft (4 to 5 m). Since it grows very quickly, it is well suited for walls and railings that need to be greened quickly.