One of the big decisions with a garden pond is whether or not to add fish. As you might expect, I have opinions on that question as well. I like fish in the garden pond. However, I like plants more. the key to a successful garden pond is having a healthy biological balance. Plants and fish can be mutually beneficial. However, many people tell me that their koi eat up their plants. So for me that eliminates koi from consideration for my ponds. Some people say there are ways to keep your plants and koi separate but I have no experience with that so use your own judgment. Another big drawback for koi is that they get large and large fish mean a larger bacterial load on the pond. This can mean a greater chance for green water or algae. Koi also require a deeper pond in our area in central North Carolina. Without koi, a pond should be about 2′ deep but with koi the pond should be a minimum of 3′ deep. This is to give them deeper cool water in the summer. Koi can also be quite expensive and it is quite discouraging to find a dead koi in your yard that has been speared by the beak of a Blue Heron.
So if koi are eliminated, what are other choices. Fancy goldfish are one option. I like Shebunkins for their colors. They can have blakc, white or “blue” along with orange. Many of them have long fins. They are not as flashy as koi but do add color. The key to a healthy biological balance is to be sure you don’t end up with too many fish. You only have so many friends to give extra fish to so that means culling the less desirable colored fish. People raise eyebrows when you mention getting rid of the black ones but the truth be told, the black ones are hard to see in a pond. One of the benefits of having fish in a garden pond is watching them. It took me some time to realize that I had two black shebunkins in my pond. I kept thinking I saw shadows as the fish would swim by but it reality it was a dark fish. I took even longer to realize that I had more than one because I had to see two at the exact same time. I believe I have two but I have no way of knowing unless I can see every fish at the exact same time. Not likely with plants in the pond.
Another issue with goldfish is that they will breed and you will have more. If the dark fish that you can’t see also breed, you could end up with a pond full of fish that are hard to see. One solution to help keep fish populations down is to only buy fish large enough to determine the sex and try to buy all males.
One question I always get about a garden pond is mosquitoes. In my opinion, garden ponds actually improve the mosquito situation in the garden. I feel this is because the water invites birds and bats that eat the mosquitoes. But to help ensure that the pond is not a breeding source, i add a local native fish called mosquito fish. These fish are small and gray do they aren’t used for color but they eat up mosquito larva. They reproduce like guppies and can be culled when the numbers get high. I use them in the garden or let my cats get them by netting them out. Hey, it’s the circle of life. (Going to see the live performance of the Lion King tonight so there’s my shout out).