Carolina Jasmine is easy to grow and flowers with abandon

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Carolina Jasmine, Valsjasmyn (Gelsemium sempervirens) This tropical evergreen creeper is admired for its abundant clusters of small, sweetly-scented, canary-yellow flowers in late winter and spring, and because it is also hardy to frost inland, it heralds spring and brightens up even the dreariest of winter gardens. Together with other spring flowering shrubs and bulbs, as well as the wide variety of annuals available to South Africans, your late winter and spring garden need never be dull again.

This quick-growing climbing vine is native to the warm temperate, subtropical and tropical coastal areas of the Americas: Honduras, Guatemala, Belize, Mexico (Chiapas, Oaxaca, Veracruz, Puebla, Hidalgo,) and the south-eastern and south-central United States (from Texas to Virginia;) and in 1924 it was named the official flower of South Carolina.

The small and slender evergreen leaves are a lustrous dark green, developing a slight yellow or purple cast in winter, and the vine quickly twines 3 to 6m. In subtropical and tropical regions it is more vigorous than in colder, frosty regions.  Its scented flowers produce nectar that attracts a range of pollinators; and the fruit is a long capsule. 

Gelsemium sempervirensGelsemium sempervirensUses:

The root and underground stem of Gelsemium sempervirens is used as an ingredient in some analgesic and homeopathic products, but its use has been limited due to its toxicity. Gelsemium is used as a painkiller for migraine headaches and for face pain (trigeminal neuralgia) caused by certain facial nerves. It is also used for asthma and other breathing problems.

In the Garden:

The twining stems of Carolina jasmine are superb for covering trelliswork, fences, arbours, pergolas, and other structures that require a light and airy creeper. The new growth will twine with abandon around a trellis or fence, but it's surprisingly tame and easily controlled.

If left to its own devices Carolina jasmine will climb up trees, scramble over fences and structures, or develop a mound of tangled stems. It makes a good informal ground cover to stabilise slopes or banks, where it can sprawl and naturalise.

 In fact, it's is so easy going you can even grow it in a large container as long as you provide support with a trellis or lattice.

Cultivation/Propagation:

Carolina jasmine grows best in temperate regions that receive good rainfall, but established plants can tolerate temperatures down to about -10°C. In cold regions this climber will do best if it is planted in a protected position in the garden, where it is isolated from fierce winter winds. In the warmer regions of South Africa it is evergreen, but in the very cold parts it becomes semi-evergreen.

Because Carolina jasmine can only tolerate short periods of drought, this vine is not suited to very hot and dry regions. It is moderately salt tolerant and does well in coastal gardens if planted slightly inland.  Although Carolina jasmine is tolerant of wind, it will look at its best if planted in the garden where it is protected from strong summer or winter winds.

In tropical climates it can creep up to 6m tall with an equal spread, but in other gardens it usually grows about 3 to 4m. If grown on a trellis or fence you will need to encourage the plant initially by manually twining it around its support.

Carolina jasmine loves full sun but can be planted in light shade. It is pH adaptable and thrives in well-drained, moisture retentive soils which are moderately fertile. Avoid excessively rich soils as this will encourage excessive leaf growth at the expense of the flowers. It succeeds in many soil types, including: sandy, sandy loam, medium loam, clay loam and clay.

Mulch the roots regularly and only fertilise 2 to 3 times during the summer growing season because overfeeding will decrease the amount of flowers produced.  A good all-purpose food for flowering plants or a rose fertiliser will suffice. Water regularly until your plant is established, and moderately thereafter during dry spells. 

Pruning can be done when the plant has finished flowering in spring or early summer, or as required throughout the year.

Propagation is by seeds, layering, or by hardwood or semi-hardwood cuttings taken in summer.  

Problems, Pests & Diseases:

This climber is quite adaptable and tenacious, with no serious disease or insect problems.

Warning:

When pruning this plant, take care as the sap may cause skin irritation (dermatitis) in sensitive individuals. All parts of the plant are toxic, containing an alkaloid related to strychnine but accidental poisoning is rare because of the plants bitterness; any ingestion is potentially deadly.