Platycarya strobilacea

Platycarya strobilacea is a deciduous tree in the walnut family. Its common name is platycarya. It grows wild in China, Korea, Japan, Taiwan, and Vietnam. Its habitats include woods, thickets, and mixed forests on mountain slopes. Some stands grow on limestone. It forms a rounded crown but can become a large shrub. Poor growing conditions may lead to this shrubby form.

Garden height varies between sources. Missouri Botanical Garden and Oregon State give 20–30 feet [6–9.14 metres]. The RHS gives 26–39 feet [8–12 metres]. Less often, trees reach 50 feet [15.24 metres]. Garden spread can reach 30 feet [9.14 metres]. The RHS gives 20–50 years to reach full size. Rough, gray bark develops cracks. The alternate, pinnate leaves reach about one foot [0.3 metres] long. Each has 7–15 leaflets with pointed tips and toothed edges. Mature leaves are dark green and lack hairs. Crushed leaves smell like black walnut. The foliage turns yellow in autumn before it falls.

Yellow-green flowers appear in June and July. They form upright catkins, with male clusters around a central female. The flowers add little show, but the fruit draws more notice. Small, winged nutlets grow in clusters that look like cones. These clusters turn from green to brown as they age. They stay on the tree into winter. Despite its family ties, this tree does not produce edible nuts.

Grow it in full sun and moist soil that drains well. It also accepts light shade in the afternoon. Rich sandy loam suits it best. The RHS also lists clay, loam, and sand as suitable. It accepts acid, neutral, and alkaline soils. Give it shelter from strong winds and space for air flow. Water deeply during hot, dry summer spells. Sources list USDA zones 6–8 and UK hardiness H6. It remains rare in gardens but suits lawns and informal gardens.

Pests and diseases cause few problems in healthy trees. Roots release juglones, which can harm nearby plants. Sensitive plants include azaleas, blueberries, peonies, tomatoes, peppers, and potatoes. PFAF reports no known hazards, but this does not establish pet safety. It records cooked young leaves as a famine food. It lists no medicinal use. Fruit and bark yield black dyes, and wood serves as fuel. Burned roots give off a scent.