Laburnum Trees and Garden Fish Ponds | Poisonous. Do Not Use
QUESTION ... Is it alright to have Laburnum trees overhanging a Koi pond? As I'm planning on building a pond close to some and I've heard they can be poisonous, but I don't know what they are harmful to. Can you explain please?
Stephen Tootle, Liverpool
ANSWER ... All parts of the Laburnum tree are poisonous, the leaves bark, wood and especially the seeds. They contain the alkaloid cytisene. Just half a dozen of the little round black seeds can kill a small child. There is a variety that has seedless pods call Laburnum vossii but that still does not solve the problem of the poisonous leaves, and even the pollen from the flowers is poisonous. Any of this material allowed to fall into a pond or pool can only have a detrimental effect on the life in the water.