The bottle tree, used as garden decor, was once thought of as a means to catch and trap wayward spirits, protecting a nearby home from harm. While cobalt blue glass bottles were the traditional shade of choice in spirit catching -- the blue featured traits of both sky and water, or heaven and earth -- any colorful bottles can be used. Placed in a location that receives sunlight, the bottle tree still has a bit of a mystical quality as sunbeams illuminate the bottles, or when a breeze creates sound over the mouths of the bottles.
Select a spot for the bottle tree that is highly visible and receives at least some sunlight. When light shines through the bottles, it makes them seem to glow a bit, which won't happen in a completely shaded area.
Dig a hole in the selected location using a digging shovel or a post hole digger. The hole should be 18 to 24 inches deep and 10 to 12 inches wide.
Pour a few inches worth of gravel into the hole. Set the post in the gravel, holding it as straight vertically as possible. Hold a level against the post until the bubble is in the center of the level window, indicating a straight post.
Pour additional gravel around the post while keeping it level, enlisting a friend to do one task or the other. Pre-mixed concrete can be used in place of the gravel instead, for a more permanent installation. Fill the hole to the top with either the gravel or the concrete. Allow concrete to set completely, if using concrete.
Fill a sink with water and soak the bottles in it to help remove their labels. Check the bottles ever half hour or so to see if the labels come off when rubbed with your thumb. If not, allow them to soak longer. Rub all the paper and glue residue from the bottles. Discard the paper mess, removing it all from the sink to keep it from washing down the drain. Set the bottles aside to dry, or dry them with a dish towel.
Determine where you'd like the "branches" of your bottle tree on the post, leaving 4 inches or so between each branch, repeating the process on all 4 sides of the post. Draw a pencil mark where each branch should be, creating as many as you'd like, but typically at least 5 or 6 per side. Keep the posts staggered slightly if you like, or more even for a uniform appearance.
Drill pilot holes for the branches, keeping the bit angled at approximately 45 degrees pointing upward so the bottles won't slide off the branches.
Insert one lag bolt per hole, tightening it with a socket wrench. Each bolt should be between 1 and 2 inches deep into the wood.
Place one bottle over each lag bolt, alternating colors or shapes if working with a variety of bottles. Step back from time to time to see if you like the arrangement. If not, swap some of the bottles for others.