Cissus trifoliata aka Vine Sorrel

Cissus trifoliata belongs to Vitaceae, the grape family. This vine climbs with tendrils that grip rocks, shrubs and trees. People call it marine ivy, marine vine and possum grape. It comes from the southern United States and northern Mexico. Its range extends south from Kansas and Missouri. It grows in woods, rocky sites, chaparral and along streams. It also grows in salt marshes.

The vine sprawls and keeps some leaves through winter. Its leaves are fleshy and glossy, with toothed edges. Each has three deep lobes or three leaflets. The leaves smell bad when crushed. Missouri Botanical Garden lists its length as 30 feet [9.14 metres]. It gives a spread of 10 feet [3.05 metres]. RHS lists a height of 5–8 feet [1.5–2.5 metres]. It gives a spread of 3–5 feet [1–1.5 metres]. These sizes reflect the different scales of outdoor and pot growth.

Small green flowers bloom in June and July. Flat flower clusters span about 2 inches [0.05 metres]. Each holds about 50 to 80 flowers. Small fruits follow, with a broad oval shape. Missouri Botanical Garden calls both flowers and fruit showy. The vine can cover fences, pergolas, arbors and small buildings. Gardeners can train it to grow against walls. It also works as ground cover or in naturalized areas.

Outdoors, give it full sun and soil that drains well. It copes with rocky ground and dry spells. It also grows in soil with a moderate moisture level. RHS lists part shade, loam and sand as suitable. The vine accepts acid, neutral and alkaline soils. For pots, RHS advises gritty compost based on loam. Give potted plants bright light through a filter. Water well during growth, but give less in winter. The sources differ a great deal on cold hardiness. Missouri Botanical Garden lists USDA zones 6–10. RHS gives H1C, with outdoor use in Britain in summer.

The vine needs little care, but rooted plants can resist removal. Pinch young shoots to help it grow more densely. Take semi-ripe cuttings in summer to grow new plants. RHS advises balanced feed each month during active growth. Repot every two or three years. Renew the compost on top each spring. Reports list no serious disease problems. Watch for aphids, scale and mealybugs. Red spider mites and whiteflies may occur under glass.