vineN. America Native

Swamp Jasmine

The Story

Plant Bio

Gelsemium rankinii is a woody, evergreen to semi-evergreen twining vine native to wet habitats across the southeastern United States coastal plain. It produces glossy dark green, lanceolate leaves and bright, unscented, funnel-shaped yellow flowers measuring up to an inch and a half across.

Unlike its upland relative Gelsemium sempervirens, this species thrives in seasonally flooded bottomlands and acidic muck while putting on a heavy secondary bloom flush in fall alongside its spring display. Unsupported plants twist upon themselves to form a dense, mounding shrub shape three to four feet high.

Uses & Benefits:

Yellow funnel-shaped blossoms create dense floral displays on trellises and arbors in both spring and fall.

Stabilizes moist creek margins and wet low spots where typical upland climbing vines fail to thrive.

Flowering stems supply nectar to native bees, butterflies, and hummingbirds while dense foliage provides bird cover.

Essentials

At a Glance

Plant Type

Vine

Height

236"

Width

71"

Light

Full Sun, Partial Sun

Zones

7, 8, 9

Water

High / Wet

Humidity

High

Lifespan

Perennial

Native To

Southeastern United States

Toxicity

High

Bloom period

Spring – Fall

In flower about 9 months of the year

Planting

How to Grow

Select a planting site in full sun or light shade with rich, acidic soil that stays consistently moist.
Work organic matter into the planting hole to enhance moisture retention.
Provide a trellis, fence, or arbor for the stems to climb, or leave open space for mounding growth.
Water regularly during dry periods to prevent the soil root zone from drying out.

Pro Tip

Prune stems immediately after the spring flowering flush finishes to control growth without cutting off upcoming fall flower buds.

Keep It Thriving

Care Guide

Do

Keep soil consistently moist to wet.
Plant in acidic soil with a pH below 6.0.
Prune immediately after spring flowering.

Don't

Do not allow the root zone to dry out completely.
Do not shear deeply into old, leafless woody wood.
Do not plant where livestock or pets might ingest plant parts.

Seasonal Care Calendar

Task	Jan	Feb	Mar	Apr	May	Jun	Jul	Aug	Sep	Oct	Nov	Dec
Fertilize
Mulch
Pest Check
Propagate
Prune

Watch Out For

Pests & Diseases

Common Pests

Common Diseases

In the Garden

Landscape Uses & Companions

Landscape Uses

Trellis or arbor cover in moist gardensRain gardens and bog marginsBank stabilization along pond edgesNaturalized informal mounding shrub

Companion Plants

Taxodium distichum Iris fulva Clethra alnifolia Ilex verticillata

Multiply

Propagation Methods

Good to Know

Common Questions

Swamp Jasmine questions

What zones can Swamp Jasmine grow in?

Swamp Jasmine is hardy in USDA Zones 7–9. Inside that range it survives winter in the ground; outside it, grow it as an annual or a container plant you protect.

Is Swamp Jasmine deer resistant?

Yes — Swamp Jasmine is rated deer-resistant. Deer typically pass it over, though extreme hunger can override any plant's defenses.

When does Swamp Jasmine bloom?

Swamp Jasmine typically blooms in spring through fall. Exact timing shifts a week or two with your zone — Sow's bloom calendar maps it to your garden.

Does Swamp Jasmine need full sun?

Swamp Jasmine does best in full sun to part shade. In hot climates, afternoon shade keeps blooms fresher longer.