In their 91 years of business, Palazzi Landscape Gardening has encountered numerous instances of downspout rainwater washing out plant beds. “The solution has always been to direct the water by an underground pipe to a drainage area,” Lou Palazzi Jr. says. “However, there have been many times when this is not practical due to an urban environment or not having a place to dispose of the water.” Here’s how to develop Palazzi’s French drain system as an alternative to directing water underground.
• Place a wire strainer at the top of the downspout to keep out leaves and debris.
• Excavate (by hand) a 10- to 12-foot-long 8-inch-wide trench starting at a 2-inch depth. Expand the depth to 36 inches over the length into a pit. If you have a heavy clay-type soil, make the pit larger for better drainage.
• Install a 4-inch, solid corrugated pipe and line it on each side with 2B clean gravel, in case of excess spillover in a heavy storm. Fill the pit with the same gravel up to 4 inches below the surface level.
• Cover the pit with landscape fabric to keep out dirt. Fill the pit and cover the length of the pipe to the surface level with top soil. Compact and seed.
NOTE: If you encounter a solid rock situation, make the trench 2 feet longer and a little wider, instead of creating a pit. Use a perforated corrugated 4-inch pipe lined on the sides and top with clean gravel. Cover, compact and seed the soil, like above.