Laburnum is native to mountains of southern Europe. It is a genus of two common species L. anagyroides and L. alpinum, although some sources also include a third species L. caramanicum which on occasion is often also treated in its own genus (Podocytisus). All parts of the tree are poisonous to humans containing a chemical known as cytisine, which has been used to help with smoking cessation because of its structural similarities to nicotine. The tree is also famed for its hard timber, ideal for making veneers and turning products such as bowls.
Culture for Golden Chain
Laburnum thrives in almost all soils but struggle in overly moist soils in winter. They thrive in full sun and partial shade and tolerate cold, exposure and pollution L. x watereri is tolerant of alkaline soils but most prefer a pH between 5 and 7. Plants reach no more than 7 m in height.
Concerns about Golden Chain
Laburnum is known to be susceptible to Phytothora and it is particularly susceptible when plants are growing in wet conditions. The tree is susceptible to the fungal disease powdery mildew. Aphids and leaf mining moths and flies are also known to cause problems. The fungal pathogen silver leaf also infects this genus however, it does not cause silvering symptom in the leaves.
Management Practices for Golden Chain
Ensure plants are not planted to deep, as this increases moisture stress leading to increased likelihood of Phytophthora infection. Treat fungal or insect pathogens with a suitable fungicide or insecticide respectively where necessary. Time pruning in late May to mid July as this is the best method of preventing silver leaf infection.