A window box planter with bright, tall and trailing flowers adds a touch of color and beauty to your home. This form of container gardening is especially useful for people who lack garden space but want to grow flowers, vegetables or herbs of their choice. Grow roses for a mini-rose garden, herbs outside your kitchen window box planter, or a blend of seasonal flowers for a colorful spray. It's not hard to hang your window box planter yourself instead of hiring a professional, even if you have no prior experience or skill in such tasks.
Move inside the room and locate studs under the desired window. To do this, place the stud finder along the surface of the wall and mark the spot where it detects a stud with pencil. Extend these marks to the windowsill so you can easily view them from outside.
Step outside and locate the stud marks on the interior surface of the windowsill. Lift the window box planter, which should have the same width as the window, and place it against the base of the windowsill where you want to hang it. Transfer the pencil marks from the windowsill to the top back edge of the window box.
Extend the pencil marks on the window planter box so they are in the exact center. Drill ¾-inch holes over the marks. These holes are larger in diameter than the lag bolts so you can adjust the planter at the end to make it level. Ideally, you need two lag bolts to support every 36 inches of window box planter length. The amount you need will depend of the length of your planter, but make sure you space these evenly apart.
Lift the window box planter in place against the wall just under the window. Poke a pencil or marker through the holes to extend the marks on the wall. Put the window box planter down again.
Drill holes into each mark on the wall, using a ¼-inch drill bit. Lift the window box planter in place again and insert a lag bolt and washer through the hole in it. Tighten the lag bolt with a wrench so it grasps the studs in the wall to firmly hold the planter in place.