Shrub · Gelsemiaceae
Carolina Jessamine
Gelsemium sempervirens
Given full sun and a sturdy support, this evergreen vine hangs fragrant yellow trumpets along its twining stems in late winter.
Full sun
Every 7–14 days
USDA 7–10
10–20 ft · 3–6.1 m
Overview
Carolina jessamine is the evergreen vine whose fragrant yellow trumpets flare open along its stems while much of the South still stands bare. The twining stems wind tightly around fences, arbors, and mailboxes, and in one fast season they spin out 12 to 20 feet of growth clothed in glossy green leaves. South Carolina made it the state flower.
Behind the show the plant carries itself easily. Hardy through zones 7 to 10, it holds its evergreen foliage through heat, keeps its leaves through drought once established, and seldom shows the chewing or spotting of pests and disease. Its one real need is full sun, since a vine in shadow runs to leaf and sets only a thin scatter of blooms.
One trait sits hidden behind the bloom. The jasmine in its common name is false, since this is not a true jasmine, and every part of it runs dangerously poisonous. The leaves, the stems, the roots, and even the sweet nectar cupped in each trumpet carry strychnine-related alkaloids, so it belongs well away from children, pets, and grazing animals.
Care
The short version: full sun draws the fullest trumpets, the soil is rich and well-drained, the water stays steady while the vine is young, and a hard cut comes right after flowering on a sturdy support.
Light
Set it where full sun reaches the foliage and the stems hang heaviest with trumpets. It will take partial shade and keep its green, but a shaded vine puts its strength into leaves and shows only a thin scatter of flowers.
Water
Keep the soil moist while the plant is young, watering every 7 to 14 days as the roots take hold. Once they run deep the vine carries drought without complaint, though a bone-dry plant drops its glossy leaves and sets fewer blooms.
Soil
It roots into rich, well-drained ground across a wide pH range of 5.0 to 8.0. What the roots want is drainage far more than any exact soil type.
Temperature
Hardy from about 10°F to 100°F (-12°C to 38°C), it holds its evergreen leaves through both Southern heat and a fair freeze. That range is what keeps it dependable across zones 7 to 10.
Humidity
Plain outdoor air suits its leaves fine, so there is no humidity target to chase. It holds up in the humid Southeast and in drier gardens just the same.
Feeding
A single balanced slow-release feed in spring, applied seasonally, is all the stems and leaves ask for. This is no heavy feeder, and too much fertilizer pushes leaf at the expense of flower.
Pruning
Cut it right after flowering, while new shoots still have time to set next year's buds. Trim to hold its size and keep the top from matting, and an old leggy vine can be taken down to a few feet above the ground to send fresh green growth up from the woody base.
Repotting
rarely
Size & spacing
Expect a fast vine that climbs 10 to 20 feet (3 to 6 m) and spreads its stems 3 to 6 feet (91 to 183 cm) wide. Give it a sturdy support and room, since the twining stems coil on and pile up growth quickly.
When to plant
Carolina jessamine opens its yellow trumpets early, often in February while the rest of the garden stays bare. Set new plants out in spring or fall, prune as soon as the last bloom drops, and a lighter scatter of flowers may reappear along the stems in autumn.
Northern hemisphere
Southern hemisphere
Typical months for a temperate climate: start earlier in warm zones, later where spring frosts linger.
- Plant: spring or fall
- Harvest: late winter to early spring (February-April), with sporadic fall rebloom
Hardiness
USDA hardiness zones: 7–10
Temperature: down to -18°C
Troubleshooting
This vine is clean-growing, its glossy foliage rarely marked by serious pests or diseases. The few problems that show up trace to how it is pruned and how much sun reaches the leaves. Match what you see below and the fix is usually simple.
A dense leafy crown above thick, bare woody stems
Left uncut for a few years, the vine layers fresh green growth over the old until the top knots into a thick mat while the lower stems thicken, go woody, and shed their leaves down to bare cord. The look comes from pruning that was skipped and from twining stems that never caught hold of a support. Cut the heavy top back to a few feet above the ground right after flowering, then wind the remaining stems onto the support so the foliage knits in evenly from top to bottom.
Fix:
- Prune hard right after flowering, cutting older top-heavy vines back to a few feet above ground level
- Train remaining stems onto the support to spread growth evenly
Glossy green leaves but hardly a yellow trumpet
When a jessamine carries dense, glossy green foliage yet shows only a scatter of yellow trumpets, the cause is almost always too much shade. Full sun is what fills those stems with bloom. Shift the vine or train it toward brighter light, and thin any overhead branches that drop shade across the leaves.
Fix:
- Relocate or train the vine into a position receiving full sun
- Thin overhead shade where possible
Toxicity
This is a strikingly pretty plant and a genuinely dangerous one. Every part, from the glossy leaves to the nectar pooled in each yellow trumpet, holds strychnine-related alkaloids, and that sweet nectar has poisoned children who took the flowers for honeysuckle. No part of it is safe to eat, suck, or chew, and the same toxin threatens dogs, cats, horses, livestock, birds, and even the honeybees that probe the blooms.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Severe
A cat that chews the glossy leaves or yellow petals can go weak and wobbly within hours, its muscles slackening, its swallowing labored, and its breath slowing to a shallow rhythm. The pupils may shift, the body cools, and seizures can follow. No nibble of any part is safe.
Dogs Severe
After a dog mouths the leaves, the twining stems, or the trumpet flowers, look for sudden weakness, a staggering gait, and trouble swallowing. As the alkaloids spread, the breath slows, the body cools, and seizures, paralysis, or death can follow. Reach a vet at once.
Horses Severe
A grazing horse can begin with muscle tremors and weakness that climb into convulsions and failing breath. Every part of the vine, leaf and stem and flower alike, is dangerous, and the fatal dose is small. Keep it well clear of pastures and paddocks.
Rabbits Severe
The same nerve poison carried in the foliage and blooms overwhelms a small rabbit, bringing weakness, tremors, and collapse. No part of the plant is safe to offer or to leave within reach.
Livestock Severe
Cattle, goats, and sheep that browse the evergreen leaves face muscular weakness, convulsions, and respiratory failure, and a small amount can kill. Fence it well out of any ground where stock graze.
Birds Severe
The alkaloids strike birds hard, and even the honeybees drawn to the yellow trumpets are poisoned by the nectar and pollen inside them. Pet birds should never reach the leaves, stems, or blooms.
People Caution
No part of this plant is food. Children have been poisoned sucking the sweet nectar after taking the yellow trumpet flowers for honeysuckle, and even small amounts can bring weakness, dizziness, slowed breathing, and seizures. Keep it away from children and wash your hands after pruning.
Treat as a deadly poisonous plant: keep all parts away from children, pets, and livestock; do not let anyone suck or eat the flowers, and wash hands after handling since the sap can irritate sensitive skin.
Helpline numbers
United States
ASPCA Animal Poison Control: (888) 426-4435 (fee applies)
Poison Control: (800) 222-1222
Canada
Poison Centres: 1-844-764-7669
Varieties
A few named selections sharpen the wild vine, mostly in the flowers, and one close relative is worth knowing where the ground stays wet.
Margarita
An extra cold-hardy selection whose yellow flowers run a touch larger than those of the species.
Pride of Augusta (Plena)
A double-flowered form, its trumpets packed with extra petals, that holds its bloom over a longer stretch of the season.
Gelsemium rankinii (swamp / Rankin's jessamine)
A related native whose scentless flowers rebloom heavily in both spring and fall and which puts up with wetter soil.
How to propagate
Carolina jessamine can be increased three ways, and because the sap inside every stem is toxic, each one closes with a wash of the hands.
Stem cuttingsEasy
Late spring to summer · Several weeks to a few months
Semi-hardwood cuttings, taken from stems that have begun to firm and brown, are the dependable way to copy a named cultivar true to type. Snipped in late spring or summer, they root over several weeks to a few months into a plant identical to the parent.
SeedModerate
Fall or spring · One or more seasons
Seed sown in fall or spring will sprout, but a named cultivar will not come true from it and the seedling takes one or more seasons to fill out. Every seed and seedling is toxic, so handle them with care.
LayeringEasy
Spring to summer · A few months
Where a low twining stem lies pressed against the soil in spring or summer, roots break from its underside within a few months, and the rooted length can then be cut free and moved.
Myths
Carolina jasmine is a true jasmine, so its fragrant flowers are safe to touch or taste.
For all the perfume rising off those yellow trumpets, this is not a jasmine, which is exactly why it is called false jasmine, and it stands among the most poisonous of common garden vines. Every part, from the glossy leaves down to the sweet nectar pooled in each bloom, holds strychnine-related alkaloids, and children who sucked the flowers have been seriously poisoned, along with pets and livestock. Never treat its yellow blooms as honeysuckle or any other edible plant.