The very best sources for this project are thrift stores, estate sales, and yard sales where wooden frames can be found in large quantities for very little money. You do not need four frames that are perfectly identical — frames that are similar in overall size and profile but slightly different in molding detail or finish can actually create a more interesting result once they are all painted or stained the same color. Look for solid wood construction rather than thin MDF or plastic frames, since the wood needs to have enough thickness and strength at the corners to accept a joining connection without splitting.
Avoid frames whose corners are already separating or whose wood feels soft and punky, since these will not hold together reliably through the project. Frames with broken glass are perfect for this use since you are removing the glass anyway — in fact, broken-glass frames are often marked down even further at thrift stores, which is a genuine bargain. Ornate frames with heavy plaster or resin detail work can be heavy, so consider whether the finished piece will need to be portable or supported before choosing very elaborate styles for a project like the hanging planter that requires the structure to bear additional weight.
Why This Project Works So Well
What makes this particular DIY idea so satisfying is that it converts something genuinely worthless — an old wooden picture frame without a purpose — into something that would cost a significant amount at a boutique decor shop, using almost no skill beyond the ability to tie a knot or operate a hot glue gun. The frames do most of the work simply by being what they are: pre-finished, detailed, structurally sound wooden rectangles with built-in character. Joining four of them amplies that character into a three-dimensional object that reads as designed and intentional rather than assembled from salvaged materials.
It is also one of those projects that scales beautifully in complexity depending on how much time and effort you want to invest. At its simplest, you are tying four frames together with twine and placing a candle inside. At its most elaborate, you are building a multi-tiered hanging garden display with reinforced joints, painted frames, and custom-cut bases. Both versions are impressive. Both versions cost almost nothing. And once you have made one, you will find yourself looking at every old wooden frame you encounter in a completely different way — not as something worn out and heading for the trash, but as raw material waiting for its second life.