Is Your Garden Pond Ready for Summer?

By Al Short, Fairfax Master Gardener Intern

pond in late spring

Garden pond in late spring

It’s time to get your garden pond ready for the spring and coming summer. Where do you start? Having rested all winter, it has accumulated leaves and debris that should be removed. Check for structural issues. Search for problems with the containment structure, the liner and the rocks and gravel around the pond edge. Has the pump been out of the pond or shut off for the winter? If so, it needs to be cleaned, reinstalled and tested. Your aquatic plants have been asleep in the bottom of the pond. Your fish will be waking up from their winter hibernation and getting active.

no cleaning

Five years and no cleaning

The three “sins” of garden pond keeping are too much debris, too many fish and too much feeding of fish. In over 20 years of owning a company that designed and built hundreds of garden ponds, I found that these three factors were the root causes of most water quality and fish-related problems.

Aquatic plant activity is controlled by water temperature, not air temperature, and water is generally cooler than the air in the spring. Many aquatic plants have been thrown away because they looked “dead” when everything else in the garden was growing. Aquatic plants should be treated like any other perennial plant. Look at your plants in terms of the need to divide, repot and fertilize them.

When you repot your plants, do not use peat or potting mix as it will float out of the pot. It is best to use gravel or the worst clay in your garden. For fertilization, use “lily tabs,” which are compressed fertilizer and can simply be pushed into the growing medium. Lilies should be fertilized once a month, and the aquatic marginal or bog plants around the edge of the pond can be fed quarterly.

garden pond

Garden pond set up for seasonal operation

Too many fish in a small pond can mean trouble. A few goldfish will live for years, will winter over, keep the pond bug free and are interesting to watch. When water temperature exceeds 50 degrees, start feeding your fish, but feed only once a day and what they can eat in three minutes. When you add water, remember Fairfax County water contains chlorine and chloramine, both of which are toxic to fish. Keep a container of “de-chlor” handy that can be purchased locally.

People are concerned about mosquitoes breeding in a garden water feature. If you have fish, your pond will never have a mosquito problem because they eat the mosquito larvae before the larvae develop. If your water feature has no fish, you can control mosquitos by using “a mosquito dunk,” which is available at garden centers. A mosquito dunk is not harmful to fish, plants and birds and works by breaking the lifecycle of the mosquito larvae.

A garden pond is a “liquid tranquilizer.” It is highly addictive and non-prescription and will bring enjoyment to you and your family throughout the season. The key is to get started properly in the spring.

Water Garden Plants, Virginia Cooperative Extension