How to Winterize a Garden Pond

Every pond owner must learn to winterize her garden pond properly, to keep the pond's ecosystem healthy and the pond equipment from damage. This is especially important for backyard ponds in cold Northern climates. At the first sign of frost, or in November for warmer zones, begin to winterize your garden pond.

Things You'll Need

• Pool skimmer (long handle with net at the end)
• Large plastic storage tubs or aquariums for overwintering plants
• Artificial lighting for plants brought indoors
• Organic mulch
• Pond bubbler or de-icer

Instructions

1. Remove excess oxygenators from the pond. These are plants that provide oxygen and act as biofilters. According to "The Practical Rock & Water Garden," thinning them out prevents rot, and the resulting unsafe environment for fish. Pluck them out by hand or scoop them out with a pool skimmer. Compost them or overwinter them.

2. 

   Remove nonhardy plants.

   Remove nonhardy water plants, such as tropical water lilies. Place in a water-filled tub or an aquarium, and bring them indoors under artificial lights. The Iowa State University Extension suggests they need light for about 12 to 18 hours a day to keep them alive but not growing. Do not feed them.

3. Cut back hardy water plants and place them on the bottom of the deepest part of the pond, if it is at least 3 feet deep. If your pond is shallower, bring them indoors for the winter.

4. Cover tender marginal plants growing around the edge of the pond with an organic mulch to protect them from cold. When the first frosts have blackened the leaves, cover them completely with about six inches to a foot of mulch.

5. 

   Take care of your fish.

   Feed your fish extra food that is higher in fiber as night-time temperatures dip below 40°F. Stop feeding the fish altogether when the water temperature gets below 45°F.

6. Move your water pump to a location midway between the bottom and the surface of the pond. It can be used to power a bubbler or to gurgle on its own to help keep the pond partially clear of ice. According to "The Practical Rock & Water Garden," don't set it on the bottom of the pond, or it will disturb the slightly warmer layer where the fish live. This can kill your fish.

7. Place a bubbler or a floating de-icer in the pond, according to the University of Illinois Extension, to keep it open in winter to prevent water quality issues from killing your fish.

8. 

   Turn off fountains.

   Turn off any fountains or pumps to flowing water courses.

Tips & Warnings

• Place a net over the surface of the pond to catch falling leaves and keep them out of the water, if you have a lot of trees in your yard.

• To calculate the water volume of your pond, see the water volume link in the resources below.

• Keeping a hole in the ice is important not only for fish, but also to keep ice from damaging the pond liner.

• Never break ice that has formed over the surface of the pond. The reverberation can harm dormant fish. If you need to open a hole in the ice, place a pan with boiling water on the ice to melt a hole.

• Do not feed the fish in winter, even if the weather warms up and the fish become more active. Wait until all the ice is gone in spring and the water temperature is above 45°F.

References

• The Practical Rock & Water Garden; Peter Robinson; 2003
• Iowa State University Extension
• University of Illinois Extension

Resources

• Cornell Cooperative Extension: Calculate Water Volume