Plants
Trumpet Vine
Campsis radicans · Bignoniaceae
Hardly any hardy climber brings as much holiday feeling to a house wall as the trumpet vine: from July to September it opens clusters of large, glowing orange trumpet flowers reminiscent of Mediterranean terraces. It climbs by itself with aerial rootlets, grows several metres tall and flowers all the more richly the hotter and sunnier its spot.
- Light
- Full sun; the more warmth and light, the richer the flowering.
- Watering
- Moderate: fairly drought-tolerant once established; water deeply in heatwaves.
- Care level
- Medium
- Botanical
- Campsis radicans
The genus comprises two species and their hybrid: Campsis radicans is the hardiest and self-clinging, while the Chinese Campsis grandiflora carries the largest flowers but needs support and mild locations. The cross „Madame Galen“ combines both and is the most reliable variety for German gardens; „Flava“ flowers pure yellow, „Flamenco“ scarlet.
The trumpet vine is a plant for the patient: in the first two or three years after planting it invests in roots and shoots and often does not flower at all — the most common cause of disappointment, but completely normal. From the fourth or fifth year it takes off and grows more opulent year by year. A warm, fully sunny spot is essential, ideally on a south or west wall.
It flowers on the current year's wood — which dictates the most important care measure: in early spring the previous year's side shoots are cut back to two or three buds, much like grapevines. This hard prune keeps the plant compact and pushes flowering; unpruned specimens age and increasingly flower only high up.
Its power deserves respect: with aerial rootlets and a strongly suckering root system, the trumpet vine can conquer damaged façades, gutters and joints. On sound, solid walls it should be given a sturdy trellis for guidance; a root barrier keeps the suckers in check. Plan for that, and it will give you pleasure for decades.
For insects the nectar-rich trumpets are a laid table into which bumblebees positively squeeze themselves. A note of caution: the sap and leaves can irritate sensitive skin — in English it is also called „cow itch vine“ — and the plant is considered mildly toxic if eaten. Better to wear gloves when pruning.
Is Trumpet Vine toxic to children and pets?
- Children
- Mildly irritating
- Cats
- Mildly irritating
- Dogs
- Mildly irritating
Leaves and sap are considered mildly toxic and can cause irritation and redness on skin contact (hence the English name „cow itch vine“). Ingestion can cause gastrointestinal upset in children and pets; wear gloves when pruning.
Typical symptoms: On skin contact: redness, itching and burning. After ingestion: nausea, vomiting and diarrhoea.
In an emergency:call the German poison control centre in Bonn on +49 228 19240 (24/7) — for pets, contact an emergency vet directly. This information does not replace medical or veterinary advice.
Overview: toxic & non-toxic plants for cats, dogs and children
Care
- 01Fully sunny, warm position, ideally on a south or west wall.
- 02Nutrient-rich, free-draining soil; water deeply during summer drought.
- 03Cut side shoots back to two or three buds in early spring — flowers appear on new wood.
- 04Tie in young plants and provide a sturdy trellis; aerial rootlets alone do not hold large plants safely.
- 05Remove root suckers regularly or install a root barrier from the start.
- 06Wear gloves when pruning, as the sap can irritate the skin.
Frequently asked
- Why does my trumpet vine not flower?
- Usually it is simply still too young: trumpet vines often flower only from their fourth or fifth year. Other causes are a spot that is too shady, too much nitrogen fertiliser (promoting leaves instead of flowers) and a missing spring prune, since the flowers appear only on new wood. Patience, sun and the annual cut back solve the problem almost every time.
- Does trumpet vine damage house façades?
- On sound, solid masonry it generally does no damage. The risks are cracked render, joints, timber cladding and roof boxes into which rootlets and shoots can grow. The safe solution is a sturdy trellis a few centimetres off the wall, along which the plant is guided and regularly pruned.
- Is trumpet vine poisonous?
- Mildly. The sap can irritate sensitive skin, and eating leaves or flowers can cause gastrointestinal upset in children and pets. Serious poisoning is not to be expected; gloves when pruning and a watchful eye with toddlers are sufficient precautions.
- How do I keep trumpet vine suckers under control?
- Campsis radicans sends out underground runners that can surface several metres away in beds or lawn. The most effective measure is a root barrier of HDPE sheeting installed about 60 centimetres deep at planting time. Existing suckers should be removed consistently along with their root section, ideally in spring.