Gynostemma pentaphyllum aka Gynostemma

Gynostemma pentaphyllum is known as sweet tea vine. It belongs to the cucumber family, Cucurbitaceae. Its native range runs from the Kuril Islands across Asia. This includes warm temperate, subtropical, and tropical regions. Sources list China, Japan, Korea, India, and Sri Lanka. The range also extends through much of Southeast Asia. It grows in open woods, thickets, and along roadsides. In China, it occurs on mountain slopes as well.

This vine can live as an annual or perennial. In cultivation, plants may last only a few years. Sources give a climbing height of 26 feet [8 metres]. Its stems trail over soil or climb nearby plants. Tendrils grip supports and help the vine climb. PFAF records leaves from May through October. It gives July to August as the flowering season. Insects pollinate the flowers, and plants are not self-fertile. Most plants bear either male or female flowers. Grow both sexes when seed production is the aim. Some plants may bear flowers of both sexes.

Choose a warm, sheltered site with some shade. Both growing guides recommend partial shade rather than deep shade. The soil should be rich and hold moisture. It must also drain well rather than stay waterlogged. PFAF lists sandy, loamy, and clay soils as suitable. It accepts mildly acid, neutral, and mildly alkaline soil. PFAF gives USDA zones 7–10 and cold tolerance near −5 to −10°C. Yet it warns that outdoor crops can struggle in Britain. Plants need a long, hot summer to do well outdoors. A greenhouse offers another way to grow an annual crop.

PFAF recommends sowing seed in a greenhouse during spring. Soak seeds in warm water for one day first. Sow two or three seeds per pot in rich compost. Keep the strongest seedling in each pot as plants grow. Move plants outside after the last expected frost. Use a frame or cloche while they become established. Gardens grow the vine for food and traditional herbal uses. Its climbing form needs supports when grown above ground.

People cook the leaves and young stems as food. The sweet leaves also provide material for tea. Chinese traditional medicine uses the whole plant as a tonic. The sources report uses for blood sugar, circulation, and liver function. These are reported herbal uses, not proof of treatment benefits. The plant also supplies ingredients for cosmetics and anti-ageing preparations. Both growing guides list no known hazards. That does not establish safety for every person or pet. PFAF lists no weed potential.