Brick planters can be simply and quickly built without the use of mortar. Build the planters around trees, along the edges of the yard or to enhance the front of of the home. Use a standard rectangular brick that matches your brick home to build tidy square planters or round shapes. For larger and more study projects, use a large retaining wall brick--these come in a variety of colors, shapes and sizes.
Determine the size of your planter. You will need to know the dimensions of the planter to buy the right number of bricks. For example, if the perimeter of your planter is 10 feet, and the bricks are 6 inches long, you'll need about 20 bricks for each layer of bricks. That's 10 feet x 12 inches = 120 inches perimeter / 6 inch bricks = 20 bricks.
Measure the ground where you will put the planter. Place a stake in the ground for each corner of the planter, or if it will be round, place a stake for four of the points of the circle. Stand back and examine the stakes to make sure it's where you want it. Check that's in an area that will get enough sun. Make sure your placement is perfect before digging.
Dig a trench to outline the planter. This trench needs to be at least 4 inches deep and a little wider than the brick. For example: a brick that is 6 inches wide would need a trench at least 7 inches wide.
Tamp down the earth. If your trench is too narrow to use a tamper, use your foot or a brick (if using small bricks) to flatten the dirt.
Fill the trench with 2 inches of gravel. Smooth it out and use a level to make sure the gravel base is as flat and level as you can make it. If the base is not level, the top of your planter will not be level. Use a tamper to compress the gravel into a firm base. If your trench is too narrow for a tamper, use a brick (if using small bricks) or your shoe, to tamp the gravel.
Lay the first layer of bricks in the trench. After the first layer is down, use dirt leftover from digging the trench to fill up the extra space in the trench (backfill). Lay the next layer of bricks, making sure that the bricks overlap each other. Continue placing each layer of bricks until the planter is as tall as you want.
Fill the planter with a layer of gravel for drainage and then fill with garden soil.