Trees require a rather substantial planting place so their roots can enlarge, although the spread and depth of roots varies among tree species. You may prefer to develop trees in containers if you’ve got a small yard or poor soil, but you must ensure that the planter is large enough to accommodate the tree at maturity. For best results, choose dwarf cultivars, which typically grow far more slowly and smaller than conventional species. You can construct your own tree planter using naturally rot-resistant timber, such as cedar or redwood. The finished planter measures approximately 36 inches tall by 33 inches wide.
Lay six 36-inch lengths of 2-by-6-inch redwood or cedar timber side by side vertically on a flat surface, pushing them as close together as you can.
Measure the entire width of the planks, which should be approximately 33 inches given the actual measurements of a 2-by-6-inch board. Cut two pieces of 2-by-6-inch lumber for this span, cutting with a 45-degree angled miter cut on each end so the surfaces of the planter piece with the sides of a photo frame. To achieve this, the base of this angle cut has to be the exact same length as the board measurement, with the top side of the plank approximately 2 inches longer.
Line up the mitered 2-by-6-inch planks using the top edge and bottom edge of this six 2-by-6-inch planks and screw into place with 3-inch wood screws, using two screws for each of these six planks. This completes one facet of the planter; you must create three more sides to complete the box form.
Stand up the four planter sides, then lining up the mitered ends of the flat boards. Drive 3-inch wood screws at an angle through every corner to assemble the sides.
Cut four 36-inch lengths from 2-by-4-inch lumber and screw them to the inside of each corner to add firmness to the planter.
Cut a square piece of three-quarter-inch plywood to fit over the base of the box, then using a circular saw. The square should be roughly 33-inches by 33-inches, but you should measure the measurements for accuracy before cutting the plywood.
Screw the plywood to the base of the planter box sides using 3-inch wood screws spaced 4 inches apart.
Drill several one-half-inch diameter drainage holes, spaced 6 inches apart, in the base of the planter box.
Line the tree planter box with black plastic sheeting to increase the rot-resistance of this timber. Poke holes through the plastic to line up with the holes through the plywood planter bottom.
Lay a piece of wire mesh hardware cloth over the dark plastic to prevent gravel and soil from falling through the drainage holes.
Spread a 2-inch layer of gravel or broken pottery pieces above the base of the tree planter.
Fill the tree planter using a potting mixture of equal parts sphagnum peat, compost and perlite or sand, leaving a few inches to the container border.
Plant the tree at the planter box to the same depth it had been implanted in the first container. Spread 2 to 3 inches of organic mulch on the surface of the potting mixture to help insulate the soil and retain moisture.