Having cared for numerous ponds in San Diego County over the past 31 years, I have come to have an opinion about many things related to pond set-up and maintenance. One of those concerns involves which animals and plants we should try to keep in our ponds. I even wrote an article about it in these pages several months ago. Obviously, Manatees and Anacondas are out, as are some smaller creatures, such as children or cats, but one sort of creature always comes to mind when I am asked about what not to include in a water garden. It is the turtle. Specifically, in my experience, the Red-eared Slider (Trachemys scripta elegans). Crayfish run a close second, but turtles are the bane of water gardeners everywhere.
The reason for the disdain with which I regard these creatures is simple. It is their predilection for sampling aquatic plants as food. I know that they are only grazing, as they are supposed to do, but sometimes it seems as if there might even be a little bit of sport in it, too. The damage that can be wrought by one or two turtles in a pond full of water lilies, Nymphaeas, is amazing. The evidence is plain to see as you approach the pond, with detached Nymphaea leaves, or small fragments of oxygenators floating around, or clogging the skimmer, or plants upturned, dug into, and otherwise molested.
It is so bad that in some cases I have refused to work on lucrative ponds because the owner insisted on keeping turtles in the pond. One fellow wanted me to bring a new set of lilies to his pond each week to replace the ones that his turtles had eaten over the course of the preceding week. I told him that that would be far too depressing to deal with, and I quit. His pond was ugly and dangerous anyway.
Each pond owner must make that decision for himself. But, the Red-eared Slider is an introduced species here in San Diego, and so should not be encouraged, in my opinion. It is from the American south, and has been introduced successfully into many areas through the pet trade. They are cute and are very easy to care for in a sufficiently large aquarium. Eventually, though, they outgrow these first containers and are either dumped outside or put into a backyard pond, from which they easily escape to join the already burgeoning population of feral, and now native born, turtles in our area.
I have seen the odd Soft-shell turtle in ponds, and once I found a snapping turtle in a pond whose brand new, and startled, owner was just as glad that I had found it, and not her. The previous owner of the house had failed to mention the nearly 10˝ diameter snapping turtle in that pond out back. But, even so, these are very rare events here in San Diego.
The predominant species in the pet trade is Trachemys (slider family), and because it is hardy and tough, it has done very well here. They can be found wandering all over neighborhoods, and might suddenly appear in a pond in which they had never been. Of course, they might just as suddenly go away, but rarely do. While they are in the pond, they bite through every plant stem that they encounter, especially Nymphaea and Aponogeton petioles. And the irritating part is that they don’t even eat the leaf that they have just severed. I think that they just eat the piece that fit in their mouths when they bite, so the entire leaf or flower is bitten off so that the turtle could eat an inch or so of stem tissue.
It is not that I dislike turtles. I just don’t want them in my ponds. If they are in the pond of a competitor of mine, that is fine, as long as it is far enough away from my ponds that no harm can come to me because, again, I don’t want them in my ponds.
It is easy enough to set up an area that is designated for turtles, and I have offered this suggestion to more than a few people who had it in their minds that they were going to have turtles. The intelligent ones take me up on the suggestion, and can then have both a lovely water garden and a lively turtle collection, just not in the same place.