Viburnum cylindricum

Viburnum cylindricum, or tubeflower viburnum, belongs to the Viburnaceae family. This evergreen shrub can also form a small tree. Its native range spans the Indian subcontinent, central and southern China, and Indo-China. It grows in forests and scrub, including woods with oak and rhododendron. Some wild sites are quite dry. Garden plants, however, need more reliable soil moisture.

In gardens, it often reaches about 16 feet [5 m]. The RHS gives a broader height range of 13–26 feet [4–8 m]. Its listed spread also reaches 13–26 feet [4–8 m]. Wild trees can reach 49 feet [15 m]. Plants take around 10–20 years to reach full size. The bushy crown carries branches with small, wart-like bumps. Its dull green leaves have a waxy surface. Each leaf is oval with a pointed tip.

Small white flowers form broad, flat clusters in mid to late summer. Each flower has a narrow, tube-like shape and pale lilac anthers. Insects pollinate the flowers, and the plant is not self-fertile. Oval berries follow the blooms. They turn red before ripening to black. The evergreen leaves, summer flowers, and changing fruit provide garden interest. The RHS suggests informal gardens and beds or borders. PFAF also lists woodland gardens, sunny edges, and dappled shade.

Grow it in sun or partial shade, sheltered from cold, drying winds. It needs fairly fertile soil that stays moist but drains well. Chalk, clay, loam, and sand are all suitable. It accepts acid, neutral, and alkaline soils. Poor soil and dry sites suit it less well. The RHS rates it H5, while PFAF lists USDA zones 5–9. Cold tolerance varies with the plant's origin. Northern sources can withstand more frost than southern ones. Propagation methods include autumn seed sowing, summer semi-ripe cuttings, and grafting.

Aphids and viburnum beetle may attack this shrub. Possible diseases include Phytophthora, honey fungus, grey mould, and leaf spot. PFAF reports cooking oil from the seeds, not edible fruit. It also records seed oil use for itchy skin and lighting. The wood is hard and close-grained. Despite these uses, the RHS warns against people or pets eating the fruit. It also advises gloves and protective gear when handling the plant. PFAF reports no known hazards, so the sources differ on safety.