Natural ponds are a bit tricky because of fluctuating water levels.  If you have a natural pond, you are probably familiar with the dead, brown line just above the water when a dry season comes and a soggy, grassy mess in wet years. 

There is no “correct” method for edging a natural pond. For a healthy pond, the goal is to avoid erosion and stop or filter lawn run-off.  I like mixing large rocks and boulders, a dock, or driftwood pieces to provide spots to walk up to the pond and for birds and turtles to sun themselves.

Below are a few beautiful pond edge options:

1. Rock: Cover the pond edge and slope with rock.  Here are a few pictures of rocks along the pond edges.  Some completely cover the edge and some mix plants with rock outcroppings. Different sizes of rock are called different things.  Gravel is smaller than 1”, decorative “rock mulch” is generally 1.5-3”, and Rip-rap is 5-10”.  Covering your pond edge with rock will require a bit of weeding each year to keep it looking clean.
   
   2. Wall: Install a retaining wall to create a smooth, clean edge.  This type is the easiest to mow and trim but installation costs are higher.  The retaining wall can be made of retaining wall concrete blocks or natural stone blocks.  Grass can be planted at the top edge of a retaining wall.  This creates a formal look but does not provide any filtration from lawn run-off.

– Natural stone blocks need minimal site prep- make a line, scrape it even, and drop the boulders in place.

– Round boulders need minimal site prep but will have space between and behind each rock that will need weed trimming.

– Retaining wall block needs more site prep as blocks require a smooth, packed base before setting (at least if you want a nice, straight wall even after a freeze/thaw cycle.)

3. Plants: Install water loving plants along with rain garden plants along the pond’s edge.  This is the best option if your pond receives heavy amounts of lawn run-off from fertilizers, pesticides, and rainwater.  By reducing these inputs, you will be reducing the food for algae growth in your pond, too! The shore line plants create pollinator habitat, songbird habitat, and control wind, wave, and rain erosion problems. The plants will need some attention each year; trimming back in the fall, and raking off dead leaves in the spring.  Until the plantings are well established, summer weeding helps prevent non-native plants from taking root.

4. Mix it up: I prefer a mixed pond edge that combines large patches of plants along with boulders or rock out croppings, and pieces of drift wood.  Small patches of “sandy beaches or gravel” can be used successfully in a mixed pond edge treatment.  This option combines filtration with user enjoyment.  The plants will need attention (see option #4.)