Carolina jessamine
Gelsemium sempervirens
also called yellow jessamine, carolina jasmine
The South's late-winter gold: fragrant yellow trumpets smothering fences, mailboxes and pinewoods from February, on a neat evergreen twiner that never gets out of hand.
- Type
- Shrub · Perennial
- Botanical family
- Mixed / other
- Foliage color
- Green
- Flower color
- Yellow
- Sunlight
- Full sun to part shade; blooms hardest in sun
- Watering
- Moderate
- Soil
- Moist, well-drained, organic
- Feeding
- Gentle all-organic
- USDA zones
- 7a–10a
- Frost tolerant
- Yes
- Plant out
- at the last spring frost
- Plant spacing
- 3 ft 3 in
- In-row spacing
- 2 ft 11 in
- Between rows
- 4 ft 11 in
- Square-foot density
- Not suited to SFG
- Root system
- Woody, and deeper than the stem suggests
- Working depth
- 24 in–4 ft
- Can reach
- 6.5 ft down where the soil allows
- Spread
- 5–10 ft across, about 1–2× the width of the plant
- Shallowest pot
- 20 in of soil
A vine puts far more below ground than its one thin stem implies, and that is where the alarming vigour comes from. Give the root run depth and drainage at planting; it will forgive almost anything done to it above ground afterwards.
The habit is Carolina jessamine’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.
- Cats and dogs
- Recorded toxic
Recorded as toxic to cats and dogs by Pet Poison Helpline.
The Pet Poison Helpline row is genus-level, Gelsemium spp., and it names dogs and cats. Our Gelsemium sempervirens sits in that genus, and the alternate names printed on the row include Carolina Jessamine and Yellow Jessamine, so the row is about the genus rather than about one member of it. The ASPCA carries no Gelsemium row under any of Carolina Jessamine, Yellow Jessamine, Jessamine or Gelsemium.
- When
- Not harvested, and not for the vase near children: every part is poisonous. Prune after the late-winter bloom.
- What to look for
- The gold flush fading in early spring; a top-heavy tangle on the mailbox or fence.
- How to harvest
- Shear it back by a third right after flowering; it blooms on old wood, so later cuts cost next year's show. Wear gloves for a big job — sap bothers some skins.
- How often
- One post-bloom shear a year keeps it full to the base; an overgrown vine can be cut hard and forgiven.
- Storing the crop
- Nothing to store. Enjoy it at nose height on the fence, and leave the honey-making to regions where the bees have other choices.
- Aphids Aphids on new growth in spring
- Every part is poisonous if eaten, so site it away from where toddlers and puppies graze
Beneficial predators that hunt this plant's pests — grow their favourite flowers nearby to recruit them. companion plant
- Aphid midge Aphidoletes aphidimyzaHunts Aphids
A tiny midge whose orange maggots paralyze aphids and drink them dry, twenty or more each. Sold as a greenhouse biological control and resident outdoors wherever there are small nectar flowers and an unsprayed aphid colony to find.
- Assassin bug ReduviidaeHunts Aphids
A patient ambusher with a curved beak it drives into whatever it catches — caterpillars, beetles, bugs, and the occasional bee, so count it a generalist rather than a specialist. It will jab a careless finger too, so admire it and leave it be.
- Big-eyed bug Geocoris spp.Hunts Aphids
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.
- Damsel bug NabidaeHunts Aphids
A slender, mantis-armed bug that grabs aphids, small caterpillars, and thrips in low crops and meadowy edges. Leave a strip of unmown grasses and flowers for it to overwinter in.
- Dragonflies & damselflies OdonataHunts Aphids
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.
- Garden birds PasseriformesHunts Aphids
Both things are true: birds strip your currants and a brood of blue tits takes several thousand caterpillars out of one fruit tree in a fortnight. Net what you must and welcome them everywhere else — a nest box near the apples is worth more than a spray.
- Green lacewing Chrysoperla carneaHunts Aphids
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.
- Hoverfly SyrphidaeHunts Aphids
Bee-mimicking flies whose legless larvae graze aphid colonies clean while the adults pollinate. A ribbon of shallow, nectar-rich flowers kept in bloom all season recruits wave after wave of them.
- Ladybird (lady beetle) CoccinellidaeHunts Aphids
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 Aphids
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 Aphids
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.
- Praying mantis MantidaeHunts Aphids
A sit-and-wait ambusher that snatches caterpillars, beetles, and anything else that wanders close — friend and foe alike, so count it a mixed blessing. Tall, structured plantings give it perches and egg-case anchors.
- Soldier beetle CantharidaeHunts Aphids
Soft-winged beetles seen mating on flower heads in high summer; adults and larvae both take aphids and soft grubs. Open composite flowers are their landing pads and hunting grounds.
- Spiders AraneaeHunts Aphids
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.
The state flower of South Carolina, and every part of it is genuinely poisonous, which is why deer walk past it. Do not plant it beside a honeybee yard: on scarce forage the nectar can harm the brood. Skin is fine; teeth are the problem.
The Cottage Garden Companion — the gardener's herbarium at cottagegardencompanion.com