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How to Finish a French Drain

In order to grow anything in a narrow, shady space, first make sure the drainage is in good shape. One good drainage method is a French drain.

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one good drainage method is French drain
  • Time


  • Price Range

    $50 - $100

  • Difficulty



Step 1: Lay the Pipes

Use perforated polystyrene pipe to create the drain system. Polystyrene pipe isn't a pressure drainage system; it will simply be sloped down the trench, allowing the water to flow away from the space (Image 1). Intersecting pipes are solid because they will draw water from surface inlets to the main drain (Image 2).

Step 2: Add the Gravel

After installing the central drain and the secondary connecting drains, backfill the trench with gravel, which will prevent soil from clogging the holes in the pipe.

Step 3: Lay Cardboard

As a final protective step, lay sections of cardboard over the trench before placing soil back over the drain area.

Step 4: Add Pavers If Needed

Place concrete step pavers in an irregular pattern down the center of the space.