Laburnum anagyroides – Common Laburnum (southern Europe, naturalised)
Habit: Large shrub or small tree, 5-7 m tall, 3-4 m wide, main branches vertically upright with loosely overhanging twigs; medium to fast-growing.
Flowers: Light yellow, loose racemes in May.
Fruits: Like beans, poisonous.
Leaves: In threes, medium-green.
Roots: Relatively shallow, not well anchored.
Demands: Sunny to slightly shady, needs warmth, moderately frost hardy, good for urban areas, sensitive to wind.
Soil: Dry to fresh, for loamy but not too dense substrates, prefers chalk.
Note: Wear themselves out with profuse flower production; they are generally short-lived; replace with new plants after 15-20 years; do not cut radically.
Hardiness: Zone 5b