Trumpet Vine
Campsis radicans
Vigorous enough to swallow a wall — but in shade, or fed too much nitrogen, it gives leaves instead of trumpets.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Orange
- Sunlight
- Full sun against a south- or west-facing wall.
- Watering
- Drought-tolerant once its roots are down.
- Feeding
- A high-potash feed in spring.
- Frost tolerant
- Yes
- Flowering
- July
- Pruning
- Cut it back hard every late winter.
- Overwintering
- Once established, it takes cold to about -10C.
- Apr–May Bud Break
- May–Jul Spring Growth
- Jul–Oct Flowering
- Oct–Nov Growing
- Nov–Dec Leaf Fall
- Jan–Apr Leaf Fall
- Plant spacing
- 13 ft 1 in
- In-row spacing
- 13 ft 1 in
- Between rows
- 16 ft 5 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody, shallow, wide and opportunistic
- Working depth
- 12–24 in
- Can reach
- 3.5 ft down where the soil allows
- Spread
- 39–52 ft across, about 3–4× the width of the plant
These roots go looking, and what they find is drains, soakaways, footings, paving and the border next door. Give it real distance from anything you would mind being lifted or blocked: the reach below ground is several times what the crown suggests.
Trumpet vine suckers from the roots many metres from the plant, comes up through a lawn and a patio, and regrows from every fragment left in the ground. Plant it against something you will never want it off, or in a container.
The habit is Trumpet Vine’s own; the figures are what that habit usually comes to at this size, not a measurement of this species. Roots follow the soil either way: a compacted pan, a high water table or heavy clay stops them well short of any of it, and deep open ground lets them go further.
- Whitefly Tiny white moth-like insects that rise in clouds from leaf undersides, weakening plants and leaving honeydew. Hang yellow sticky traps and encourage or introduce parasitic wasps.
- Powdery mildew A white dusty coating over leaves and shoots when roots are dry but the air is humid. Keep plants watered and mulched, prune for airflow, and remove the worst leaves.
- Failure to flower, usually from too much shade or too much nitrogen
- Suckering into the surrounding ground where the climate is warm
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Big-eyed bug Geocoris spp.Hunts Whitefly
A stubby 3 mm bug with enormous wrap-around eyes, working the soil surface and the low foliage for aphids, mites, thrips and insect eggs. It is the main natural check on chinch bugs in a lawn and it is killed outright by insecticide.
- Dragonflies & damselflies OdonataHunts Whitefly
Aerial hunters that take mosquitoes, midges and small flies on the wing all day, and whose larvae spend a year or more clearing the same insects from the water. A pond with planted margins and no fish is the way to have them.
- Green lacewing Chrysoperla carneaHunts Whitefly
Its bristly larvae — "aphid lions" — impale aphids, mealybugs, thrips, and mite colonies, eating hundreds a week. Adults feed on nectar and pollen from small open flowers and overwinter in hollow stems left standing.
- Ladybird (lady beetle) CoccinellidaeHunts Whitefly
The gardener’s favorite ally: adults and their alligator-shaped larvae each eat thousands of aphids, plus scale, mealybugs, and other soft-bodied sap-suckers. Grow flat, open flowers for the adults and never spray a colony that ladybird larvae are already working.
- Minute pirate bug Orius spp.Hunts Whitefly
A pinhead-sized true bug that is the best natural check on thrips, and happily spears aphids, mites, and insect eggs too. It needs pollen when prey is scarce, so keep something flowering nearby.
- Parasitic wasps Braconidae & TrichogrammaHunts Whitefly
Tiny, stingless wasps that lay eggs in or on caterpillars, aphids, and moth eggs — the white cocoons riding a hornworm are their calling card, so leave that caterpillar be. Umbel flowers with shallow nectar keep the adults fuelled.
- Spiders AraneaeHunts Whitefly
Webs, ambushes, and night patrols make spiders the garden’s steadiest generalist predators, taking whatever flies or crawls past. Mulch, ground cover, and undisturbed corners keep the population dense.
Green-leaved shrubs, like this one.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com