Shrub · Gelsemiaceae
Carolina Jessamine
Gelsemium sempervirens
Set against full sun and a sturdy support, this evergreen vine drapes a fence or arbor in fragrant yellow trumpets by 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 that brings the South its first warmth of the year, opening fragrant yellow trumpets while the rest of the garden still keeps to itself. Trained over a fence, an arbor, or a roadside mailbox, it softens hard lines and gives an entrance something to greet visitors with, and in a single fast season its stems can stretch 12 to 20 feet. South Carolina thought enough of it to name it the state flower.
As a fixture it earns its place with very little asked in return. Hardy through zones 7 to 10, it carries the heat of a long summer, accepts drought once it has settled, and seldom troubles the gardener with pests or disease. The one thing it insists on is full sun, since a vine left in shadow turns leafy and forgets to flower, and the whole point of planting it is the show.
One detail is worth weighing before it goes in. For all the jasmine in its name, this is not a true jasmine, and every part of it is dangerously poisonous. The leaves, stems, roots, and even the sweet nectar carry strychnine-related alkaloids, so it suits a setting kept well clear of children, pets, and grazing animals.
Care
The short version: give it full sun for the fullest display, rich well-drained soil, and steady water while it is young, then prune hard once the flowers fade and set it against a sturdy support to climb.
Light
Place it where it gets full sun and the bloom comes on at its fullest, the better to put on a show. It tolerates partial shade and holds its green, but a shaded vine trades flowers for foliage and the corner looks thin on color.
Water
Keep the soil moist while the plant is young, watering every 7 to 14 days through its first season. Once the roots have settled it carries drought with ease, though a vine kept bone-dry sheds leaves and gives fewer flowers.
Soil
It settles into rich, well-drained ground across a wide pH range of 5.0 to 8.0, which makes it easy to place almost anywhere. Drainage counts for far more than the exact character of the soil.
Temperature
Hardy from roughly 10°F to 100°F (-12°C to 38°C), it weathers Southern heat and a fair cold snap alike. That comfortable range is what makes it a dependable presence across zones 7 to 10.
Humidity
Ordinary outdoor air is all it asks, so there is no humidity target to chase. It is at ease in the humid Southeast and just as content in a drier garden.
Feeding
A single balanced slow-release feed in spring, repeated seasonally, is the whole of its appetite. This is no hungry plant, and a heavy hand only pushes leaves where you wanted flowers.
Pruning
Prune right after flowering, while there is still time for new growth to set next year's buds. Cut to hold its shape and head off a top-heavy tangle, and an old leggy vine can be taken down to a few feet above the ground to draw fresh growth from the base.
Repotting
rarely
Size & spacing
Plan for a fast climber that reaches 10 to 20 feet (3 to 6 m) and spreads 3 to 6 feet (91 to 183 cm) across. Give it a sturdy support and room to roam, since it twines and gathers growth quickly.
When to plant
Carolina jessamine opens the gardening year early, often in February while everything around it waits. Settle new plants in spring or fall, prune as soon as the bloom fades, and a quieter second flush may arrive to close the season come 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 keeps its composure, with no serious pests or diseases to manage through the year. What few quibbles surface come down to how it is pruned and how much sun reaches it. Find the look you are seeing below, and the remedy is usually an easy one.
A lopsided canopy that leaves the lower frame looking bare
Allowed to run for several years untouched, the vine layers fresh growth over old until a heavy crown sits above stems that have gone leggy and bare, and the whole arrangement loses the tidy line a wall or arbor wants. The reasons are ordinary: pruning that got skipped and stems never guided onto their support. Bring the top growth back to a few feet above the ground once flowering ends, then settle the remaining stems onto the structure so the cover reads full and even again.
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
All greenery, none of the golden show
A jessamine that fills out beautifully yet withholds its flowers is almost always settled in too much shade, and the display a sunny corner would deliver simply never arrives. Full sun is what brings the bloom. Shift it or train it toward a brighter aspect, and lift any overhead branches that keep the spot dim.
Fix:
- Relocate or train the vine into a position receiving full sun
- Thin overhead shade where possible
Toxicity
This is a plant of real beauty and real consequence. Every part holds strychnine-related alkaloids, the sweet nectar among them, which has poisoned children who took the flowers for honeysuckle. No part of it is safe to eat, suck, or chew, and the same toxin reaches dogs, cats, horses, livestock, birds, and even the honeybees that visit the blooms.
Toxic to
Cats · Dogs · Horses · Rabbits · Livestock · Birds · People
Cats Severe
A cat that chews any part can grow weak and unsteady within hours, with slack muscles, labored swallowing, and breath that slows and shallows. Pupils may shift, the body cools, and seizures can follow. No nibble is a safe one, so keep a roaming cat well away from where it grows.
Dogs Severe
After a dog mouths the leaves, stems, or flowers, expect sudden weakness, an unsteady gait, and trouble swallowing, then slowed breathing, a cooling body, and seizures, paralysis, or death as the alkaloids work. Reach a vet at once if a curious dog has access to the planting.
Horses Severe
A grazing horse can begin with muscle tremors and weakness that climb into convulsions and failing breath. Every part of the vine is dangerous and the fatal dose is small, so keep it nowhere near pastures or paddocks.
Rabbits Severe
The nerve poison that fells far larger animals overwhelms a small rabbit, bringing weakness, tremors, and collapse. None of the plant is safe to offer or to leave within a rabbit's reach in the garden.
Livestock Severe
Cattle, goats, and sheep that browse the foliage face muscular weakness, convulsions, and respiratory failure, and a small amount can kill. Fence it out of any ground where stock graze.
Birds Severe
The alkaloids strike birds hard, and even the honeybees drawn to the blooms are poisoned by the nectar and pollen. Pet birds should never reach the leaves, stems, or flowers.
People Caution
No part of this plant belongs at the table. Children have been poisoned sucking the sweet nectar after taking the yellow 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 handful of named selections lend the wild vine a little polish, and one close relative is worth a thought where a corner of the garden stays damp.
Margarita
A more cold-hardy choice for cooler gardens, and one that carries flowers a touch larger than the species.
Pride of Augusta (Plena)
A double-flowered form that keeps the display going across a longer stretch of the season.
Gelsemium rankinii (swamp / Rankin's jessamine)
A related native with scentless flowers that rebloom generously in spring and fall and suit a damper corner of the garden.
How to propagate
Carolina jessamine can be carried on in three ways, and since the sap is toxic, each one closes with a wash of the hands.
Stem cuttingsEasy
Late spring to summer · Several weeks to a few months
To carry a named cultivar forward true to type, semi-hardwood cuttings are the dependable route. Taken in late spring or summer, they root across several weeks to a few months into a plant faithful to its parent.
SeedModerate
Fall or spring · One or more seasons
Seed sown in fall or spring is an option, though a named cultivar will not come true from it and the plant asks one or more seasons to establish. Since every seed and seedling is toxic, handle them with care.
LayeringEasy
Spring to summer · A few months
The simplest path of all: where a low twining stem rests on the soil in spring or summer it roots itself within a few months, ready then to be severed from the parent and moved.
Myths
Carolina jasmine is a true jasmine, so its fragrant flowers are safe to touch or taste.
Despite its name and its perfume, this is no jasmine, which is precisely why it answers to false jasmine, and it counts among the most poisonous vines a garden can hold. Every part, the sweet nectar included, carries strychnine-related alkaloids, and children who sucked the flowers have been seriously poisoned, as have pets and livestock. Never treat its yellow blooms as honeysuckle or any other edible plant.