I have a bunch of these that might work great as planter boxes. They are very well made and durable. Black painted outside on front and 2 sides and bottom has black ribbed rubber on it so it wont stain through or rot your deck. They are not very tall though, so great for seedlings or you could easily build up the sides to your desired height. 45.5"l x 16"w x 5.5"h. currently have 40 available so you can buy as little or as many as you like. $5.00 each, pick up in colwood, no long holds