Water lily leaves are often prized for decorative purposes but, from time to time, the leaf population in a pond or lake can explode. If more than half of the water is covered in leaves, you may have a problem to solve. Water lily leaves can be removed physically or chemically, but both methods can be time consuming. It is not recommended to remove all the water lily leaves that float on a body of water, furthermore, as they often serve to oxygenate the water for fish and provide shade for all sorts of aquatic living species.
Steps
Method 1 of 2: Physical Removal
Step 1. Row through the lily pads on a boat
If the body of water in question is a lake or large pond, and you want to remove the water lily leaves to open a passage for boats, rowing a boat through the water lily leaves is often enough to open a passage and keep it open.. It is better to do this with a rowboat rather than a motorized one, as water lily leaves can potentially get caught in the engine.
Step 2. Rake away the lily pads
If the pond is relatively placid and the leaf roots aren't too twisted, raking the surface is a viable solution for removing water lily leaves. Take the rowboat to the center of the pond, or walk there if the water is shallow enough. Use a regular garden rake to pull the lily pads off the surface of the water. Some sturdier varieties may have tough roots which make this difficult, and you may not be able to remove the water lily at the root. This solution works well for the short time, but the lily pads will usually start growing again after a while.
Step 3. Fill the fish pond
If water lily leaves are growing in your private pond, adding several large carp (be careful not to become invasive) or other fish that feed on water lilies can naturally reduce the amount of leaves that form on the surface. Typically, add two fish every 4000m2 of water is an efficient amount. Fish should be young, as they eat more than older fish.
Step 4. Use a spade
This method works best with shallow ponds that you can wade through, and is difficult to use for larger ponds and ponds. While standing in the water, dip the metal tip of the spade under the root of the lily pad. Break the root off the ground and then lift the free leaf from the surface of the water. This solution can be time-consuming, and may be difficult to implement if the pond is large and working alone. However, it is very effective, and it removes the water lily problem literally at the root.
Step 5. Try an "aquatic lawn mower"
It is a tool that works like an ordinary lawn mower, except it cuts the weeds and vegetation that grow on the surface of a body of water. It is usually used against algae, but it also works well with water lily leaves. This particular lawn mower can be used from a boat, so it works in both deep and shallow ponds.
Method 2 of 2: Chemical Removal
Step 1. Use chemicals after the main flowering period is over
Chemical treatment is the most effective and is less likely to cause permanent damage to the pond's ecosystem when the first "batch" of water lily leaves of the season has withered.
Step 2. Understand where to apply the treatment
The chemicals are usually applied from the center of the pond outward, acting on small sections at a time. Spraying the entire pond all at once can cause too many plants to decompose and could deprive the aquatic life below the surface of valuable oxygen. To avoid this, apply the treatment first to overdeveloped areas of the pond and then attach other small sections after a few weeks.
Step 3. Apply a surfactant for agriculture
Applying a herbicide directly to the water lily leaves might work, but often you'll need to apply a surfactant first to dissolve the protective wax layer on the outer layer of the leaf. Spray the surfactant liberally over the leaf.
Step 4. Choose the right type of herbicide
Glyphosate-based herbicides are most commonly used in waterlily leaf removal, but imazapyr-based herbicides will work as well. Both are broad-spectrum, non-selective herbicides that essentially kill every surface plant they come in contact with, but neither harms the plants that live below the water's surface.
Step 5. Apply the herbicide to the top of the leaves
Follow the instructions on the herbicide label to determine the right dosage. Usually, herbicides for aquatic plants are sprayed directly over the top of the leaves until they completely and evenly cover the surface.
Step 6. Rake away the dead lily pads
The herbicide will kill the plant, leaving it dead floating on the surface. Walk in the water or use a rowboat and rake away the lily pads. Bring out the roots, too, if possible. Even though the herbicide should have killed the roots, it won't do the pond any good to leave too many dead roots at the bottom, which will eventually rot.
Step 7. Repeat this process for several weeks
Wait two to three months between applications, spraying a small section at a time to keep the pond ecosystem from losing its balance. After the entire pond is covered, return to the areas already treated if too many lily pads survived the first pass.
Warnings
- Wear protective clothing when removing lily pads from your pond or lake. At a minimum, you should wear waterproof boots and clothing when wading the pond to apply a cure. When using chemical remedies, you should also wear protective gloves and goggles.
- Learn the rules governing the removal of aquatic plants. An illegal removal could result in a fine. When it comes to removing plants from your own pond, the rules should be more lax, but still require a permit. Be well informed before taking any action.
