natural pond maintenance (frog friendly)
We have a pond, spring and run off fed, about 100x30 feet, unknown depth. Has great frogs, possibly fish. We got it last year, did nothing with the pond and it became completely covered with algae and plants. I would like to maintain it better but do not want to damage it for aquatic life nor kill the frogs/tadpoles. I have been raking off the algae but someone suggested that might be making it worse as more sun penetrates. It does not have a bubbler or fountain. We do have geese, mallards, occasional herons and other birds.
There are multiple kinds of algae and plants in many layers of the pond. Filamentous green hovers below surface. yellow/green thick and velvety on the surface, various pond bottom growers, plus some edging plants that survive under the water when it is high and take over the edge of the pond when the water level goes down. I'd love feedback on the suggestions on maintenance: possible chemicals, food coloring, store bought algae eaters (from the master gardener), aeration systems and dredging. I have searched for a pond maintenance company but have only found those who do manmade ponds, coi ponds, etc. Thank you for your help (and recommendations for my own use or to local resources if you know of them).
Jackson County Michigan
Hello Natural Pond Owner,
Thank you for contacting eXtension regarding your pond. You have a beautiful natural pond. so what is wrong with it again? Someone thinks you have too much algae and you got helpful advice from lots of people? Actually, algae is a normal part of pond life. It comes and goes in the spring and fall naturally due to "turnover". This is normal.
I notice from your photos that you are mowing right to the water's edge. This practice allows for surface water to runoff during a rain event to flow directly to your pond. I discourage this practice. Rain water runoff carries lots of extra nutrients from the soil into the water feeding the algae every time it rains. If you are fertilizing your lawn near the pond you are unwittingly magnifying the effect from this practice. I can give you lots of advice about how to manage the algae in your pond but this is becomes meaningless if the root of the cause is not corrected. To use a colloquial phrase, “you have to stop feeding the beast.”
So what are a few first steps to get started?
1. Create a buffer strip of either grasses (Stop mowing right to the water edge.) or landscape with native plants that will serve as both a buffer and add natural beauty attracting butterflies and birds. You can leave an open space or create paths to the pond edge for access, but the majority of your pond should be shrouded in shrubs, grasses and other water loving plants. This will protect the edge from erosion and stabilize the shore as well as buffer the water from runoff. It will also help reduce the access of geese to your lawn. (Geese don't like tall grasses.)
2. Do not fertilize within 25’ feet of your pond and use a phosphorous free fertilizer such as a 12-0-12 or something of the like on the rest.
3. It is OK to remove the excess algae with a rake, compost more than 50’ feet away from the water’s edge.
4. If you remove the nutrient loading problem you will see a reduction in algae growth. However if you are looking for faster results, you can put something in the pond if you want. Blue dyes are the least harmful and deny the blue spectrum light that the plants require, killing the algae and a few Submergent plants. It will turn everything blue and makes it hard to see the fish and frogs. I recommend dyes for fountains, garden ponds and ponds that experience an overall pea soup green algae problem. Aerators or floating fountains are effective. They cost electricity and add maintenance but can work wonders.
5. OR do nothing to your pond beyond adding a buffer strip, and love it in all its natural changes.
Here are some websites for more information:
I hope this helps.