Crossvine (Trumpet Flower) care

Light

Crossvine is what florists mean by "bright spot, no direct sun" — close enough to a south or east window to feel the brightness, with a sheer curtain or a few feet of distance keeping the sun off the leaves. Thrives in full sun to partial shade. Flowers most profusely in full sun but tolerates woodland-edge light conditions where other climbers struggle. Morning sun with afternoon dappled shade is acceptable in hot southern climates. A phone lux-meter at the leaf surface should read 1,500-3,000 lux at noon.

Watering

Water crossvine weekly when young; established plants are drought-tolerant. The actual day count varies with pot size, light, and season — the finger test (or lifting the pot to feel its weight) is more reliable than a fixed calendar. Empty any drainage saucer afterwards so the pot isn't sitting in water. Young plants require consistent watering to establish deep roots over the first 1–2 seasons. Once established, crossvine is notably drought-tolerant and requires supplemental water only during extended dry spells.

Soil and pot

Crossvine grows best in adaptable — accepts clay, loam, or sandy soils. One of the most soil-tolerant native vines available. Grows well in average garden soil without amendment. Slightly acidic to neutral pH (5.5–7.0) is ideal, but it tolerates a broader range. Good drainage is preferred but not critical. A pot with a working drainage hole is non-negotiable for this species — even free-draining mix will turn soggy in a closed planter. If you love the look of a decorative pot without a hole, use it as a cachepot around an inner nursery pot you can lift out to water.

Humidity and temperature

Crossvine sits happiest at around 40–70% humidity and -20–38°C (-4–100°F). Native to the humid southeastern United States and naturally adapted to typical garden humidity levels. No supplemental humidity is required outdoors. Indoor plants in dry environments may benefit from occasional misting. If you keep the room above year-round and avoid placing the plant near a cold draught, a hot radiator, or an air-conditioning vent, you have already handled the two biggest indoor stressors.

Fertilising

Feed crossvine sparingly. Generally requires little supplemental feeding in garden soils. If growth is poor, apply a balanced slow-release fertiliser in early spring. Avoid excess nitrogen, which promotes foliage at the expense of flowers. Skip fertiliser entirely on a stressed, recently-repotted, or actively wilting plant — fertiliser salts make damage worse, not better. Wait for a round of healthy new growth before resuming a feeding rhythm.

Common problems

Below are the issues we see most often on crossvine in the Growli community. Each is annotated with the most common cause so you know where to start.

• Invasive spread — Crossvine spreads by root suckers and can become difficult to contain in fertile soils. Install root barriers, remove suckers promptly, and prune annually to maintain boundaries. Not considered invasive in its native range but can be vigorous in enriched garden beds.
• Sparse spring flowering — Flowers form on previous year's wood. If the vine is pruned in late winter or early spring, the flower buds are removed. Prune only immediately after flowering ends in late spring or early summer.
• Leaf scorch in extreme heat — Foliage may scorch or partially defoliate during periods of intense summer heat above 38°C combined with drought. Provide a deep mulch around the root zone and water during extreme heat events.

Propagation

Root cuttings taken in late winter are the most reliable method. Semi-hardwood stem cuttings also root in summer. Can be grown from seed, though germination is slow. Layering a flexible stem to the soil surface roots readily. Propagation is the cheapest, most satisfying way to expand a collection — and it doubles as insurance against losing a mature plant to an accident. Take a backup cutting once the parent is established and healthy.

Toxicity to pets

Crossvine is mildly toxic to pets. Bignonia capreolata is in the Bignoniaceae family. ASPCA does not specifically list this species. No well-documented systemic toxicity is recorded, but some sources note potential mild skin or digestive irritation from sap. Classified as mildly toxic out of caution; keep pets and children from ingesting plant material. If you keep cats, dogs, or curious children in the house, weigh placement carefully — a high shelf or a hanging planter is enough for casual safety. For severe ingestion incidents, call your local vet and the ASPCA Animal Poison Control Center (in the US, 888-426-4435).

Pet-safety status is sourced from the ASPCA Toxic and Non-Toxic Plant List, which catalogues the most-asked-about plants for cats, dogs, and horses.

Crossvine deep-dive guides

Every aspect of crossvine care, each with its own calibrated guide:

• Common crossvine problems & fixes
• Crossvine watering schedule
• Crossvine light requirements
• Best soil mix for crossvine
• Crossvine fertilizing guide
• When to repot crossvine
• How to propagate crossvine
• How to prune crossvine
• What's eating my crossvine?
• Crossvine growth rate & size
• Crossvine cold hardiness
• Crossvine temperature & humidity
• Is crossvine toxic to cats & dogs?
• Is crossvine toxic to cats?
• Is crossvine toxic to dogs?
• Getting crossvine to bloom

Featured in these plant shortlists

Crossvine qualifies for 6 curated Growli shortlists — each one filtered objectively from our structured plant-care library, so the selection is consistent and checkable:

• Best plants for a north-facing window — Houseplants for a north-facing window: bright, even, indirect light and no scorching direct sun. Each pick verified against its documented light needs.
• Best drought-tolerant houseplants — Houseplants that prefer to dry out — forgiving of forgotten watering and ideal for travel or busy weeks.
• Best trailing & climbing houseplants — Vining and trailing houseplants for shelves, hanging pots, and moss poles — selected by growth habit.
• Best flowering houseplants — Indoor plants grown for their blooms — selected from the flowering species in Growli’s plant-care library.
• Best houseplants for a cool room — Houseplants that tolerate cool conditions down to about 10°C — for an unheated spare room, hallway, porch or a home kept cool.
• Best fast-growing houseplants — Houseplants documented as fast or vigorous growers — quick to fill a pot, cover a pole or trail down a shelf.
• Browse all 29 plant shortlists — pet-safe, low-light, drought-tolerant and more

Related guides

Crossvine is also known as Crossvine, Trumpet Flower, and Quarantine Vine.

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• All 8452 plant care guides in the Growli library