Culture
Best grown in organically rich, medium moisture, well-drained soils in full sun to part shade. Best in full sun, but appreciates some part afternoon shade in hot summer climates such as the St. Louis area. Performs poorly in the heat and humidity of the deep South (south of USDA Zone 7). Best performance generally occurs in climates such as the Pacific Northwest where both summer and winter temperature are moderate. In St. Louis, it is best sited in a protected location to minimize risk of damage from sub-zero winter temperatures. If trained as a small tree, root suckers must be removed as they appear. Also consider removing the seedpods as they appear because they are not particularly ornamental, they consume plant energies and they are quite poisonous.
Noteworthy Characteristics
Laburnum × watereri, commonly called golden chain tree, is noted for its pendulous axillary racemes of yellow, wisteria-like flowers that bloom in spring. This hybrid is a cross between L. alpinum and L. anagyroides. It typically grows 25-30’ tall as a tree, and 15-20’ tall as a shrub. Trifoliate, clover-like, medium green leaves (to 3” long) produce little fall color. Pea-like yellow flowers in racemes to 15” long appear in a profuse, often spectacular, late spring bloom. Flowers give way to seedpods that ripen in the fall. This hybrid usually produces a sparser crop of seedpods that its parents. All parts of this tree are poisonous.
Genus name is the Latin name.
‘Vossii’ is a cultivar that produces pea-like yellow flowers in drooping racemes to 24” long in a profuse and often spectacular late spring bloom.
Problems
Twig blight is an infrequent but potentially serious disease. Canker and leaf spot are lesser disease problems. Watch for aphids and mealybugs.
Uses
Small specimen tree. Also may be grown as a large shrub. Train for arbors, pergolas or espaliers. Good background plant.