As we start into summer, many ponds and lakes have become choked with algae and weeds from a full summer’s growth turning water features into water hazards. Since water is a major feature of many courses, from rivers to ponds, managing weeds and algae can greatly increase the visual appeal of the course. But leaving the ponds to manage themselves can lead to an unsightly mess, decreasing the enjoyment of your guests and causing maintenance frustration.
Below we will cover several strategies for taking care of current weed problems as well as improving your pond year after year to ensure it stays in better shape with less effort. The strategies below are all effective but finding the right combination for your specific water features and needs will vary from property to property and pond to pond. Like turf, ponds and rivers are living things and are effected by a large number of factors that can make management difficult. Once you find the right solution, improvements will be noticeable. Many management techniques also have the added benefit of mitigating other problems such as mosquitoes and bad odours in the pond.
- Aquatic Weed Cutters and Rakes: Aquatic weed cutters and/or rakes allow you to manually remove and control a large number of aquatic plants and algae. This is something generally done later in the summer when weeds have started to grow at heavier densities. The advantage to this method is that it allows you to selectively address problems in highly visible areas. By removing the actual plants, you are also removing the nutrients tied up in them. With less plant matter decomposing in the pond, there is less nutrients to feed future growth. The disadvantage is that you will likely have to remove the plants several time throughout the summer to maintain control which can be labour intensive.
- Beneficial Bacteria: By introducing a population of beneficial bacterial to your pond in the presence of aeration you can reduce nutrient loading and prevent excessive weed growth and algal blooms. The bacteria will actually break down the nutrients in the pond and move them into an animal based food chain rather than plant growth. These bacteria will break down both water soluble nutrients and/or sludge bound nutrients. There are a variety of bacteria types available to target different problems such as the sludge layers. Most bacteria work their best at warmer temperature so start now to get ahead. The bacteria are safe for fish and humans and are an environmentally sound method of keeping your pond healthy and nutrient levels in check.
- Pond Dye: A great way to prevent weed growth in your pond is by depriving plants of the light they need to grow. This is a simple and effective way to reduce plant growth in your pond. Pond dye is easy to add to your pond as it will mix itself through the water over the course of a few hours. This dye is non-toxic and safe for all wildlife and can be added at higher levels to increase its effectiveness. This method is best used when the plants are not yet at the surface of the pond, for example; in the spring or after manual removal.
- Aeration: By adding aeration to the pond you will improve its overall health and prevent many potential problems. The benefits of aeration are many and they include: reducing oxygen stress of fish (summer and winter kill), removing toxic gases from your water (getting rid of unpleasant odours), circulating the water (destratification), improving bacterial activity and the decomposition of organic material (reducing eutrophication, some algal problems and sludge build up). There is also a reduction in mosquito larvae in the water body due to circulation. Aeration can also reduce fish deaths during excessive weed growth or algal bloom by maintaining oxygen levels and preventing them from dipping to toxic lows. Oxygen levels are most likely to dip in the few hours prior to sunrise, so if using a timer this is the most crucial time to run aeration.
- Reducing Nutrient Inflow: By using buffer zones and carefully planning water flow, you can reduce the amount of nutrients that enter your pond. This means minimizing water flow from nutrient rich zones like fertilized plant beds and lawns. These nutrients can increase the amount of weed and algae growth that you experience. Any unabsorbed fertilizer, compost or manure from these areas will lead to increased growth rates of aquatic plants and algae. When possible, water from these source should be diverted away from the pond.
Every pond is unique due to soil chemistry, water chemistry, biological demand, and the presence of diverse organisms and as such many challenges can be encountered. If your pond has become a problem, contacting a knowledgeable supplier is often the best route to take.
