Catalpa ovata aka Chinese Catalpa

Catalpa ovata is a deciduous tree native to China. Common names include Chinese catalpa, yellow catalpa and Japanese catalpa. It belongs to the trumpetvine family, Bignoniaceae. It grows in woods, open land and along woodland edges. Wild plants occur at heights up to 8,200 feet [2,500 metres]. Garden trees often reach 20–30 feet [6.1–9.1 metres] tall and wide. The RHS gives a taller range of 26–39 feet [8–12 metres]. Its spreading branches form a rounded crown, though growth can become uneven.

The gray-brown bark has ridges and deep cracks. Large, pale green leaves give the tree a coarse look. Each leaf can reach 0.8 feet [0.25 metres] long and wide. Leaves have heart-shaped bases and pointed tips. Their edges may be smooth or have three to five lobes. Fine hairs grow along the veins beneath otherwise smooth leaves. Leaves grow in whorls and turn dull yellow in autumn. Wind and hail can tear them as the season goes on.

The bell-shaped flowers are cream to pale yellow. Orange and purple spots mark their throats. Upright panicles carry the small flowers above the leaves. Missouri Botanical Garden places bloom in May and June. The RHS reports flowering from mid to late summer. Long, thin pods follow the flowers and hang from branches. They change from green to brown as they ripen. Pods reach about 1.3 feet [0.41 metres] long. They split along their length, releasing seeds with white fluff.

Grow this tree in sun or partial shade. It prefers fertile, moist loam with good drainage. It also accepts clay, sand and chalk across varied soil pH. Established trees tolerate dry, poor soil and brief flooding. Shelter helps protect the large leaves from strong winds. Young plants need protection from late spring frosts. Sources list USDA zones 4–8 and UK hardiness H6. The tree provides shade and suits rain gardens or difficult sites. Its leaves feed catalpa sphinx and tersa sphinx caterpillars. These moths provide food for birds and bats.

Branches can break, and caterpillars may cause heavy leaf damage. Leaf spots, mildew, twig blight and verticillium wilt can occur. The RHS also notes rare cases of honey fungus. The tree seeds freely and has spread beyond gardens in America. NC State warns that it shows signs of becoming invasive. PFAF reports cooked flowers and young pods as edible. It lists no known hazards, but this does not establish universal safety. PFAF also records the stems as a strong diuretic.