Develop a natural pond
By C. Levesque
Unlike a fish pond, a natural pond attracts frogs, dragonflies, birds ...
Three square meters are enough to create a small paradise of biodiversity. Both useful and decorative, the natural pond has many advantages.
Here's how to create a natural pond.
Where to dig a pond?
Preferably in a dry, flat place at the lowest level. There shouldn't be too many trees around so that the leaves don't rot.
Also avoid areas that are too sunny or too hot to prevent the water from evaporating too quickly.
How to dig the pond?
Anticipate the use you will make of the extracted soil (embankment, around the pond, square vegetable garden, etc.). Materialize the contour in curves using a string. Use a water level (around 20 €) so that the edges are on the same plane.
The ideal is to dig successive levels (by renting a mini-excavator): first remove 40 cm over the entire surface, then form steps of 40 x 40 cm, to a depth of 80 to 120 cm. This part will remain frost-free in the winter and will not dry out in the summer. Preferably form a gentle slope on the north shore.
Waterproof the bottom of the pond
Use a black PVC tarpaulin (1 to 2 mm thick) the size of the pond, plus its depth and 30 cm on each side. Remove roots and protruding stones and cover the soil with 2 inches of wet sand.
Lay out the geotextile then the tarpaulin, fixing them provisionally to the banks with earth and stones (final stowage will be done after filling the water). Place a 2-inch layer of sand and clay where aquatic plants will root (avoid potting soil).
How to fill the pond with water?
Ideally, filling with rainwater can be supplemented with water from a well or, failing that, with tap water, which is expensive and chlorinated, and therefore less recommended.
Which plants to install in a natural pond?
Ban exotic species. Collect a few plants from around a pond in the surrounding countryside, at the rate of one or two specimens of shore plants (forget-me-not, rush, aquatic mint ...), semi-aquatic plants (water iris, reed ...), floating (lenses, water lilies) or submerged (milfoil, waterweed). Transplant them before the end of June in a pot weighted with a stone.
Keep a small beach without plants for birds to come and drink. Frogs and dragonflies will spontaneously populate this small nature reserve!
Maintain your pond
In the fall, mow bank plants and remove invasive submerged plants. Leave them for a few days at the water's edge so that the small invertebrates can free themselves.
- After a few years, partially clean out the silt that collects at the bottom to prevent the pond from suffocating.