Summer is approaching and the desire to be outside and enjoy the farm ponds comes right along with it.

Excessive surface plant growth takes away the beauty of the ponds and can also destroy the natural balance of the pond. Managing the plant growth effectively will sustain ponds for longer periods of time.

Aquatic plant growth is a necessity in any pond. Without plants, many other aquatic organisms would die. The additional oxygen and food that plants provide ensure stability within the pond. In addition, some plants reduce erosion and provide for nesting and insect cover as well.

However, too much aquatic plant growth can become a nuisance. Duckweed and watermeal are prime examples of this. These fast growing organisms can reach undesirable levels in less than a month and leave your pond surface covered in green. Once the surface is covered, sunlight is reduced for other plants and oxygen levels are depleted. If severe enough, biological, chemical or mechanical methods of control are encouraged.

Mechanical control can consist of using a small seine or fine mesh to drag the floating debris off the surface. This method however, is only temporary. Other methods would include diverting nutrient rich water runoff away from the pond. Nutrients from septic tank seepage, fertilized lawns or feedlot runoff all contribute to excessive levels of nutrients in the pond which encourage plant growth. Another measure to take would be to drain the pond and deepen it if it was too shallow or had a layer of black muck at the bottom. This serves as storage for excessive nutrients.

Biological weed control is another method, but tends to be less effective. Grass carp will eat floating duckweed and watermeal, but unless there are plenty of carp to keep up with the excessive plant growth, little difference is made. The final method of control that one can choose is chemical.

Chemical contamination of domestic water supply is a consideration. There may be a waiting period for watering livestock, eating fish, or swimming. Use caution and follow the label carefully. Chemicals are an effective control, but they can also be expensive. Retreatment may also be necessary for an effective job. Decaying material may cause a lower level of oxygen. Dividing the pond into sections and treating a portion of the pond may be the best option.

Using any one of these controls or a combination can be effective, but only when used wisely. Contact your local extension office if you would like a guide sheet on aquatic plant control and the steps to take in caring for your beautiful ponds and summer enjoyment.

Kevin Hansesn is an ag business specialist for University of Missouri Extension in Livingston County.