Few will argue that the sight of water lilies adorning still freshwater ponds and lakes, or slow moving rivers is truly beautiful. In fact, they inspired Claude Monet to paint over 250 pictures of them in his garden in Giverny.
The large, glossy dark leaves are anchored by long stems to rhizome roots, which are fleshy tubers that store nutrients, and the flowers are held just above the water by short stems. Water lilies do provide many benefits, offering a resting spot for dragonflies and frogs as well as shade for the fish and invertebrates beneath. This shade also benefits the water by preventing the growth of algae.
However, despite their beauty water lilies can bring their fair share of problems to the aquatic environment. In the right conditions, they can grow excessively and quickly take over a body of water, out-competing native plant and reducing biodiversity.
While some shade is a good thing, when the entire surface of the water is covered in lily pads the temperature of the water is increases as they absorb sunlight; Stagnant areas are also created with low oxygen levels which negatively impacts on the natural balance of the body of water and the life forms it supports; Any leisure activity such as fishing, swimming or boating becomes impossible.
Water Lily Control
Spraying with an approved herbicide can be carried out, though it needs approval of the Environment Agency and can be an expensive option as it requires qualified operators who are licensed to carry out the work. This method often requires repeat applications before the problem is solved. It also creates the added problem of leaving rotting vegetation in the lake, which can cause de-oxygenation and increased nutrient build up.
However, the most effective way to control water lilies is with removal of the root system. This could be carried out manually, but is very labour intensive and therefore costly. However, mechanical means of removal dramatically reduces the time taken to get the job done, and allows for very thorough removal of the root system to help delay regrowth.
How Aquatic Solutions can help
Using the excavator attachment on our Truxor amphibious machine, water lily rhizomes can be grubbed out in next to no time, and the work can be targeted to leave enough of the water lilies to take advantage of their beauty and benefits, while reducing the negative impact that an “infestation” will bring.