Pond liners are generally made from composites such as heavy PVC or butyl rubber sheeting, or are preformed, hard plastic molds. Their drawbacks are the exposed bare black or dark green of the liners at the top edges of ponds, and the inorganic look of them within a pond. Camouflage or mask the hard, unnatural surfaces of pond liners to make them unobtrusive, give your pond as organic a look as possible, and create a haven for pond wildlife.
Camouflage the Base of the Pond Liner
Lay 2 inches of sand and pieces of old carpet on the bare earth. This ensures that no sharp stones or tree roots will come to the surface and damage the liner when the weight of the water presses down. (Ref 2) Lay out the pond liner or inset the mold into the hole you have dug for the pond, and spread the liner out across the whole area.
Cover the base of the liner or mold with gravel and large, smooth rocks or stones. These provide anchors for plants, hiding places for pond life, and interesting detail for anyone looking into the pond.
Shovel in a layer of garden soil to cover parts of the base of the pond. Soil provides anchorage for aquatic plants, camouflage for small pond creatures, and completes the disguise for the bottom of the pond liner or preformed mold. Keep the nutrient-rich topsoil aside for planting above ground or in aquatic plant pots, and use the deeper layers of earth.
Fill the pond slowly to within two inches of the top of the pond. Use rainwater collected in a rain barrel as the preferred option, or fill with a garden hose attached to a faucet. The weight of the water pulls the liner in a little, so adjust the weights holding it in place to allow for movement. Leave the pond for two days to allow the sediment to settle completely before doing any planting, and for any chlorine from the mains supply to evaporate.
Disguising the Submerged Sides of a Pond Liner
Use bricks or stones to disguise the pond liner on steep edges, securing them with concrete for stability. Source old bricks for the aesthetic of color and texture. If the bricks are very old there may still be remnants of lime mortar attached. Peter J. May, in PondLandscaping.co.uk, advises that bricks should be painted with a silicon-based waterproofer, and treated and washed several times before complete immersion. This will stop any lime from leaching into the pond and damaging plants, fish or other pond creatures such as snails and frogs.
Build up from the bottom, creating gaps where plants can fit and pond wildlife can hide. Randomize the arrangement to give the suggestion of an old, natural feature within the pond. Make sure that the bottom layer has no sharp edges which might puncture or damage the pond liner.
Extend the brick or stone up to the top of the pond. Cover the overlapping pond liner with earth and plant with ground cover, moss or grass to blend the edges together naturally.
Hide the Top Edge of the Liner
Dig a shelf or tier 8 to 10 inches below the top edge of the pond, all the way round the inside of the perimeter. Drape the liner over this shelf and weight it down with large rocks and stones. Extend the liner up over the edge of the pond to a width of at least 8 inches. Secure the top edges with more rocks and stones.
Fill the pond to a level of 2 inches from the top edge of the pond. The large rocks and stones mask the pond liner behind, so that the water laps up against them, disguising the ledge. Replace small sections with aquatic plants in mesh pots weighted with gravel.
Disguise the top edge of the pond with marsh-loving plants such as gunnera, marsh marigolds, pickerelweed and ferns, and allow ground cover to grow over the edge to soften the line.
Disguising the Top Edge of a Preformed Mold
Use paving stones to create a slight overhang if you have chosen not to use bricks and stones to line the mold. This has the effect of hiding the top few inches above the waterline.
Avoid accidentally tipping the slab when standing on it, by leveling the ground around the pond, applying a layer of concrete and then cementing the slabs into place. Follow the instructions on the cement mix package for the optimum consistency and setting time.
Fill spaces between the paving slabs with earth and ground cover plants to soften the lines. Scatter wildflower seeds if you want to attract butterflies and bees, or plant ground hugging plants such as Bellis perennis, more commonly known as the English daisy.