Here are this week’s gardening questions and answers, provided by Parker County Master Gardeners. To submit a question, send it to firstname.lastname@example.org. For more information about Parker County Master Gardeners, or to become a member, call 817-598-6096 or visit www.pcmg-texas.org.
How do I winterize my backyard pond and protect my fish during the cold weather?
The first thing to do is stop feeding your fish. When the water temperature reaches 55 degrees Fahrenheit and remains there for several days, the fish metabolism slows down and feeding them becomes harmful. Fish cannot digest their food because they do not have a stomach, just a long intestinal tract. The food simply stays in their digestive tract and rots, causing death. I have already stopped feeding my fish and tucked them in for winter.
I usually start decreasing the amount of food in early November. Then I watch the weather forecast and check the water temperature as the cold fronts come through. The warmest area of the pond is the bottom, so the fish will go there and stay until the temperature of the pond warms up in the spring. As the weather warms, you will notice the fish becoming more active; and that will be your sign to start feeding again.
Since fish are slow-moving in the winter, I recommend you add a large rock or other structure where they can go for protection from blue herons, raccoons and other predators. Most fish are colorful, and they can’t easily escape. If their enemy spots them, they are lunch. The rock will help conceal them.
The plants in my pond are hardy in Parker County and go dormant during winter. I have anacharis (Egeria densa), lizard’s tail (Saururus cernuus) and water lilies (Nymphaea). As the foliage dies back, I remove it so that it doesn’t foul the water. My water lilies are hardy (not tropical), and I simply prune them back in the fall because they make a mess in the bottom of the pond. My pond is happy with these three plants but a larger pond could accommodate more.
I have placed a large black net over the pond to keep the falling leaves out. The net keeps the skimmer from being overloaded with leaves and keeps the pond clean. The net makes a huge difference in pond maintenance. Falling leaves will rot in the bottom of the pond and require draining and cleaning come spring.