A pond situated near some large deciduous trees, especially in fall, can be a lovely and picturesque sight. However, the chore of removing leaves from the pond's surface is far less lovely. Fortunately, this chore can be avoided altogether by simply not allowing the leaves into the pond in the first place. How?
Around the time you expect leaves to begin falling and cluttering your pond, drape some pond netting over it. This screens the pond from leaves that fall or blow into it. Once the leaves are done falling and you have raked the area around the pond, you can remove the pond netting and its covering of fallen leaves all at once.
You may wonder why it's necessary to go to all this effort just to keep a few leaves out of your garden pond. In fact, dead leaves and debris are not just unpleasant to look at; they threaten the health of your pond and its inhabitants. As they decay, chemicals are released which will encourage algae growth and perhaps even threaten the health of your fish directly. Keeping your pond clear of dead leaves is a way for you to significantly reduce your risk of "winter kill."
What is pond netting? Just as its name implies, it's a fine mesh net made from flexible plastic. With the wide range of sizes available, you may be able to find one that will cover your pond completely all by itself. Otherwise, you may need to select several pieces. Make sure to allow for enough overlap between them to prevent gaps from forming - that would defeat the purpose of having a net at all.
You may choose to weight your net with bricks or stones at the edges of the pond, or to purchase pegs that are pushed through the net into the ground much like a tent peg in order to hold it in place.
Of course, not all pond netting is created equal. Different manufacturers and product lines offer different mesh sizes for you to choose from. Coarse netting is of limited utility - while it will catch large leaves easily, smaller leaves and pieces of leaves will drift right through into the water. Also, if coarse nets are allowed to droop into the water, they may act as "gill nets", trapping and killing the unlucky fish who tangle with them. If you do choose a coarser net, which is more appropriate for keeping fish safely in the pond, be sure to suspend it well clear of the water.
To avoid these problems, choose a fine net, with a mesh size of no more than a half inch (approximately 1 centimeter). Smaller mesh, such as three-eighths of an inch, may be even better. These finer-meshed nets will not only catch all sizes of leaves, but other debris as well: acorns, for example, and even the maple-tree "spinners" or "helicopters."
The most basic pond-netting technique works best on smaller ponds. Simply lay the netting across the pond surface and fasten the perimeter of the net every few feet. You can use stakes, clothespins, wire, bricks or stones; there are many possibilities. Remember, the netting should not be allowed to sag into the water, though. If necessary, get some inexpensive PVC pipe segments and lay them across longer reaches of the pond to support the net.
A slightly more complex pond-netting method which pays off later is to use those PVC pipes to construct one or more frames to which the netting is attached with cable ties. Once the frames are built, you can lay them across the pond, making for a neater look and for easier maintenance as well.
Whatever method you use, make sure that the netting is well enough supported so that little or none of it touches the water. This will minimize the risk of fish entanglement, as well as slowing leaf decay and keeping the pond surface clear.
It is important to clear the netting of leaves on occasion. For one thing, as the leaves dry, they will become crumbly and fall through the net, causing the very problems the netting is designed to prevent. For another, as leaves accumulate and grow wet from dew or precipitation, they will get heavy enough to stretch the netting into the water or perhaps even tear it.
This is where the time put into making PVC frames can pay off. If you used small PVC frames, you can simply flip the leaves out onto the ground to be raked away and disposed of. If you have a larger PVC frame, you may want to enlist the aid of at least one other person to minimize leaf spillage into the pond.
If you used stakes instead of frames, remove those stakes along one side of the netting, then fold it in half. You may be able to flip the leaves out from there, or it might be better to un-stake the rest and gather the netting into a bag, dragging the leaves free of the pond before dumping them out. Again, when handling a large section of netting, get someone to help you if possible.
Pond netting can keep out more than debris; it can also discourage pond pests and predators. This is particularly true of birds such as herons. If this is a problem you'd like to address, choosing a finer mesh of darker-colored plastic will make the netting more easily seen. If pests see the net, they are less likely to get themselves entangled in it.
So far the discussion has centered on keeping things out of your garden pond. You can also choose netting to keep fish in your pond. This may be especially appropriate just after you add new fish to your pond, for the first week or so, to encourage them to get comfortable in the pond rather than roaming around outside it. In this case, a coarser mesh can be used, but as mentioned above, be careful not to use such a coarse mesh that the fish can get through - or halfway through.
It's so much easier to enjoy your pond when you don't have to work so hard on keeping it clean. Take some time in the fall to plan and install some pond netting. It will free up the time you'd otherwise spend fishing for dead leaves.