Water quality:
Small garden ponds may grow algae, which turns the water green. Algae may “bloom” periodically, often in spring when the water warms, but persistent green color indicates excess nutrients. In these cases, increased water flow (flushing, more pump capacity), filter maintenance, or treatment may be needed.
Filtration:
There are several types of filters that collect debris. Inspect all filters periodically and flush when necessary.
Pond bottom:
Aquatic plants lose leaves, particularly during colder months. This dying plant matter can lead to poor water quality and a lack of oxygen for fish and native wildlife. Remove leaves and organic debris before they accumulate.
Fertilization:
Aquatic plants may need fertilizer during their growing season, depending on the nutrients in your natural soil.
- Liquid fertilizers are effective in ponds with floating leafed plants. Follow the label directions for amount and timing.
- Avoid overfertilizing that causes excess algae.
Chemical control:
In small ponds, unwanted plants can be managed by manual removal, and small amounts of algae or duckweed can be dipped out with a fine mesh net.
When persistent algae or undesirable plants cannot be controlled by hand, specific herbicides may be necessary. Check the label to determine if the herbicide will kill your desirable plant species.
- Use non-toxic herbicides labeled for aquatic use (many common garden herbicides are not to be used in ponds).
- Follow label directions for how much and how often to apply.