Best plastic planter boxes Hanover 20-Inch Black Resin Square Planter What you need to know: This is one of the better-looking plastic planter boxes.

If either of these are the case, consider turning a planter into an umbrella stand; you'll have a handy base for your patio umbrella and grow decorative plants or perhaps a mini-herb garden.

Best plastic planter boxes Hanover 20-Inch Black Resin Square Planter What you need to know: This is one of the better-looking plastic planter boxes.