Mandevilla boliviensis aka White Dipladenia

Mandevilla boliviensis, or white dipladenia, is in the Apocynaceae family. This woody vine winds its stems around supports to climb. Kew gives its native range as Bahia in Brazil. RHS gives a wider range, from Costa Rica to Bolivia and Brazil. Kew places it in a wet tropical climate. It suits warm spaces, not cold sites outdoors.

In gardens, it grows about 8–13 feet [2.5–4 metres] tall. It spreads about 3–5 feet [1–1.5 metres] wide. RHS says it takes five to ten years to reach full size. Its glossy, oval leaves are about two to four inches long. It keeps its leaves when the air stays warm enough. Winter cold can make it shed them. RHS thus calls it semi-evergreen, not fully evergreen.

The white flowers have a tube shape and yellow centres. They grow in small groups of three to seven blooms. Each bloom is about two to three and a half inches across. RHS gives mid- to late summer as the bloom time. Missouri Botanical Garden gives a less exact term: seasonal bloomer. The flowers give the vine its main value for show. Its stems can climb trellises, fences, poles, arbors and pergolas. It also grows in patio pots or greenhouses.

Give it bright light, but shade it from hot sun under glass. Missouri Botanical Garden lists full sun to part shade. Use loam-based, peat-free compost that stays moist but drains well. RHS accepts acid, neutral and alkaline soils. Give it a site out of strong winds outdoors in summer. In Britain, it suits a warm greenhouse or conservatory. Young plants in pots can stand outside in summer. RHS rates it H1C; Missouri Botanical Garden lists USDA zones 10–11. In colder regions, grow it in pots or as an annual.

Prune in late winter or early spring. Sow seeds in spring and give them warmth. Take softwood cuttings in late spring, or semi-ripe cuttings in summer. RHS says to heat cuttings from below to help them root. Both garden sources report few serious disease problems. Watch for spider mites, whiteflies and mealybugs, even in winter storage. Eating the plant may cause a mild stomach upset. Its sap may also irritate skin. RHS says to wear gloves and other protection when handling it.