Main picture above: Poisonous Laburnum Tree
I Lost Two Koi In One Week
QUESTION: My neighbor had a laburnum tree, which was growing over my pond. The leaves, blossom, and seed pods all fell into the pond and my Koi ate the blossom as the skimmer couldn’t remove them quickly enough. I lost two Koi in one week with strange symptoms, so I finally went round and asked if they would cut it down. I explained the problem and told them it was a poisonous tree and to my surprise, they agreed.
They cut it down last weekend and my Koi seem less shy and are feeding more than when the tree was there. My neighbors want a new tree to replace the laburnum but I don’t know what tree I can buy that will be safe for the fish. It will be in the same place and will eventually hang over the pond, I don’t mind the falling leaves as long as it is not poisonous. Please can you suggest what I could buy them?
ANSWER: It might seem a tall order to replace the spectacular display of the poisonous Laburnum with something equally impressive, but really there are plenty of small trees that will flower and possibly fruit or give a stunning display of autumn color without poisoning the inhabitants of a pool.
Another prerequisite, I presume, is that it is a tree that will grow fairly quickly to maturity, whilst remaining relatively small. Some of the Mountain Ash fits this bill. They don’t cast too much shade and their root system stays compact and unintrusive. Sorbus aucuparia ‘Asplenifolia‘ has elder-type umbels of flower in spring followed by bright red berries in autumn when they are almost eclipsed by the stunning red foliage. Or there is the “Japanese Mountain Ash”, Sorbus Matsumura with more large orangey/red berries.
Other small trees definitely to consider are the huge range of (and often forgotten) Crab apples such as Malus floribunda, “The Japanese Crab”, or the stunning and scented Malus “Pink Perfection”. Also, there are the Hawthorns or Mays, particularly if you need something really tough and hardy. Craetagus oxycantha ‘Coccinea Plena’ often called ‘Paul’s double scarlet’ is very popular or the Crataegus prunifolia for its autumn color. The fruit makes great food for the birds.
If berries are a problem then go for a silver birch. Betula dalecarlica, ‘the Swedish silver birch’ is my favorite with its light foliage and gradually whitening bark.
Deadly and Poisonous Climbing Plants Around Garden Ponds.
Always avoid deciduous Climbers
Q. I remember reading an article that went through the climbers and plants that should be avoided around ponds. I am in the process of finishing my pergola and was looking for some help in identifying which climbers to use (preferably evergreen). Can I use ivy?
All deciduous climbers should be avoided. This will rule out some of the most poisonous species of climbing plants.
From the evergreen climbers, there is still a tendency to drop leaves at some point in the year. Then there are the flowers themselves that will drop petals. They are not poisonous in themselves, but unless you have a skimmer system they could clog up a prefilter to a pump.
In this respect, Ivy is good because it only flowers once it has reached a certain height or age and the resultant seed is poisonous in excess. A small-leaved or variegated variety is easy to keep in hand and can be prevented from flowering by keeping it cut back to the height up to which it grows
The dust from the ivy glue and the ivy anchor roots are an irritant to some people and animals.
An attractive alternative evergreen and variegated climber, not often considered as such, is the Euonymus fortunei ‘Silver Queen’. I have seen it clamber up twelve feet of wall with no problem and it hardly flowers at all. If it does produce the occasional flower it is best pruned out because the resultant seed is a strong purgative not necessarily appreciated by fish