If you are a pond keeper it is imperative to ensure that certain species of tree that are poisonous are kept away from your fish pond. The vast majority of species shed their leaves, particularly during the fall. The last thing you want is for your Koi and other pond fish to eat the leaves, as they fall into the water.
Even if the leaves are not poisonous the increased levels of organic matter falling into or blowing into the pond is bad news; the leaves eventually decay on the pond floor. Decaying vegetation increases the levels of ammonia and carbon dioxide; nobody wants that!
A net covering is a viable solution but does in my opinion detract from the overall look and feel of the pond; needs must in many cases however!
You may think that I'm okay because I have a pond surface skimmer to remove the leaves. Although the pond skimmer will remove the leaves, it may not do so in time. Koi are inquisitive, hungry creatures that will investigate any new pond presence pretty much straight away!
The right selection of tree species will certainly provide a welcome respite for your Koi, goldfish, toads and other aquatic life from a hot summer day, as its shadow prevents the water from heating quickly.
The welcoming shade helps to block out UV rays, in turn helping to control the build up of suspended algae and blanket weed. The cooler water helps oxygen to dissolve from the atmosphere into the water much more easily.
When selecting trees to place around a pond avoid the following, or select them at your peril! The laburnum, bay, laurel, yew and lime tree all cause problems. Other species, whilst not necessarily poisonous have large root systems that will eventually interfere with your liner pond; the poplar varieties, willows and sycamores are examples to avoid.
The following list is suitable for planting in backyards, containing a fish pond or water garden:
* Some of the ash tree varieties are a good choice, as they do not cast too much shade and their root system does not spread like wild wire. The Mountain ash has elder type umbels of flowers in spring, followed by bright red berries in the fall that are almost eclipsed by the stunning red foliage. The Japanese Mountain Ash produces large orange berries.
* Crab apple trees are a fairly small tree species that are a great choice for landscaping around a fish pond. The Japanese Crab apple and the scented Malus Pink Perfection are good choices.
* Other good choices are Hawthorns or Mays, particularly if you need something really tough and hardy. Why not try the Crataegus prunifolia for autumn colour.
* The Swedish silver birch (Betula dalecarlica) is great if you are looking for light foliage and a bark that gradually goes whiter over time.
If you have an outdoor pergola, situated near to your pond and are looking to add some evergreen variegated climbers then make sure that you avoid deciduous climbers, such as ivy. This plant species is amongst the most poisonous of all climbing varieties.
If you are determined to select evergreen deciduous climbers then the Silver Queen (Euonymus fortunei) is a great option as it grows rapidly and hardly flowers at all; occasionally it does produce flowers but you can easily prune it back.
By Sean Roocroft