This self watering planter uses the water from the eaves trough and a wicking system.
Step 1: Layout
Lay down sand or gravel and then a base like patio blocks as a foundation for where your planter is going to be. Build a frame in the outline of your planter.
If your planter is low, don't seal off the ground with the patio blocks so the roots of your plants can access the soil underneath.
Step 2: Building the Planter
Add the back and board it up first. It is easier to attach the back when it is away from the wall and it is harder to move the planter away from the wall and back after the rest of the planter is done so that's why you do the back first. Once the back is finished and the planter is in position, continue adding levels to the base.
When calculating the height, I measured how high I needed to be get up to the vinyl siding and then went to the next multiple of 3 1/2 inches so that the 4 x 4's would end up even with the top of the planter. The left side of the planter has 2 x 6 walls so I had to rip one board so it would come out to the 31 1/2 inch height.
Step 3: Bench (optional)
Cut 2 x 2's the length of the bench space. Find the seat curve you want by experimenting with cardboard or tracing the curve of an existing chair that you like. Alternately, you can just make it flat. Cut multiple support boards in the shape of the curve and attach two of them to the two sides. Lay the 2 x 2's across and then place the remaining support boards underneath them and attach them to the back. Cut 2 x 12's or other large stock on a 45 degree angle and use them to brace up these middle support boards.
The back should lean two inches from top to bottom. Cut wedges that start at two inches wide and taper to nothing and screw them to the back, the same distance apart as the seat supports. For the length of 80 inches, I used four supports evenly spaced.
Starting at the front of the seat, screw the 2 x 2's on, leaving a 1/2 inch gap between them. When going up the back, measure the total distance of the back first and then adjust the size of the gap so that the top 2 x 2 will be even with the top of the planter.
Step 4: Self Watering System
If your planter is high, make a floor by screwing supports to all sides and then laying in boards. Otherwise, you will need a lot of soil to fill the planter and it will be too deep for the water to wick all the way up to the plants.
Lay a length of weeping tile (the kind without the holes in it) along the bottom of the planter. I used two lengths of weeping tile as I have a drain pipe coming down each side of the building. If your planter is wide enough, you could run it along the length of your planter and back. That way it will have more of a reservoir of water. If your boards aren't tight, add vapour barrier underneath the weeping tile. Screw strapping at each end to hold down the weeping tile as it makes its 90 degree angle.
For the wicking material, I ordered a 15 foot roll of lantern wick from Amazon and cut it into 11 inch lengths. With an exacto knife, cut slits the size of the wick in the top of the weeping tile about every 15 inches. Slide a wick down each hole so that the wick touches the bottom of the weeping tile.
Drill an overflow hole and insert an overflow pipe just below the top of the weeping tile. This should be at the opposite end of the weeping tile from where the drainpipe enters. I used 1/2 plastic pipe and sealed it with silicon where it enters the weeping tile. The exterior diameter of 1/2 plastic pipe is 7/8 inches so that is the size of drill bit you will need. I also ran the overflow pipe into the lower planters since they have no weeping tile in them.
Direct your drain pipe into the weeping tile and seal the gap between the drain pipe and weeping tile with plumbers putty or other appropriate material so that soil won't go down and clog up the weeping tile.
Step 5: Add the Soil and Plants
As you are adding the soil, keep the wicks standing straight up by packing the first few shovelfuls of dirt around them. When you are adding your plants, be careful not to disturb the wicks.