Autumn Care Guide for Garden Ponds

As most terrestrial gardeners know, autumn is not only the time to wrap things up from this year’s endeavors, but also the time to set things up to get a great start on next year’s. An hour or two of preventive maintenance in October can make a lot of difference in what a pond will look like in May.

Leaves… Ahhhh, Fall… That beautiful time of year when the leaves turn gorgeous shades of yellow, orange and red and flutter gently to the – bottom of your backyard garden pond. Not only is this an unattractive mess for you to clean up, but toxins produced by decaying leaves is one of the primary causes of fish loss over the winter months.

One of the most effective and inexpensive methods to prevent leaf buildup is to install pond netting. Simply stretch the mesh over the water and stake into place around the perimeter. Alternately, leaves can be scooped up in a long-handled fish or skimmer net, but this takes a lot more time and effort, and is far too easy to put off once the water begins to chill. Pondkeepers who installed skimmer/overflow boxes when they built the pond have a big advantage here. Most of the leaves quickly get trapped in the filter box, and are easily removed. There are also portable skimmers that can be installed in an existing pond that are quite effective as well.

More leaves… Not all leaves that end up in ponds come from trees. The water lilies, marginals, aerator and floating plants all have leaves that rot and decay in the winter months, too. As the weather gets cold, and leaves begin to wither and die, they should be removed immediately. The common floating plants like water hyacinth and water lettuce generally cannot be wintered without a greenhouse, and probably are best discarded. Hardy water lilies and marginals should be cut back drastically, leaving at most an inch or two. Tropical plants should be removed from the pond altogether at this time. For more details on wintering water garden plants, please see Winter Care for Garden Ponds.

Other debris. Over the spring and summer months, most ponds build up a fair amount of fish waste, garden dirt, soil from dumped plant pots and other debris that also decompose and release toxic compounds. This decomposition process has been going on constantly during the spring and summer without problem, because actively growing plants utilized some of these compounds, and a fully open water surface allowed others to easily escape. A fall cleaning is highly recommended to remove as much of this waste as practical before the pond ices over. It is certainly not necessary to remove every tiny bit of debris, but netting or vacuuming a good percentage makes a huge difference.

After the fall cleanup, the addition of one of the bacterial products like Sludge Digester can help speed up the decay process of the remaining debris. This will again lessen the risk of winter losses and will help get the pond of to a great, clean start come spring.

Feeding the Fish. In colder water, fishes’ digestive systems are sluggish. On the other hand, the final few weeks of fall are the last chance for fish to bulk up for their winter rest. The best option for the hobbyist is to feed easily digested foods, especially those made from wheat germ, when the pond temperature drops below 55o F.. Feeding should be stopped altogether when the pond temperature drops below 45o F.. Wheat germ foods should be again utilized in the Spring, when the water temperature is between 45o F. and 55o F., to provide an easily digested diet after the long cold winter.

Related article: Pond Netting