How to Build a Vegetable Garden Box for Your Deck

My sister and her husband have a large, sunny backyard, but they prefer to leave that space open for pickup football games and other neighborhood fun. (They have four children of their own and lots of little visitors.) So, when they decided they wanted to grow some vegetables, the solution was to build a deck-side garden.

My brother-in-law, John, is an engineer, so he had no problem coming up with a good-looking, efficient design. It’s also easy enough to construct that you don’t have to be an engineer to build one. So, here’s John’s Deck Garden — and thanks to my sister, Elly, for sharing the photos. (By the way, these are larger photo files, so feel free to click on the thumbnails to get a closer look at what’s happening.)

John and Elly wanted a garden large enough to grow a couple of tomatoes, some basil and a few other herbs, so they decided to build a box 6 feet long by 2 feet wide. After buying 1-by-8 cedar boards for the sides, some 2-by-2 lumber for the support pieces and a piece of plywood for the bottom, John (with assistance from my dad) went to work. He cut the lumber to size, then used wood glue to attach the boards on top of the plywood bottom (above). He then attached the supports inside the box (below) He started building the box, attaching the side pieces to the supports using deck screws. (This is where having two people working makes the job much easier.) He built it one layer at a time, so that the final box is about 22 inches deep.

adding support to deck box — Once the bottom was attached to the first row of boards, an internal support was added.

Once the box was complete, John flipped it over and attached four strips of 2-by-2 to the bottom to raise the deck garden off of the deck. It’s not shown in the photo, but he also drilled some drainage holes in the bottom and lined the box with landscape fabric. The fabric helps the bed retain some moisture and the holes make sure it doesn’t retain too much.

man's foot in garden box — John’s 6-foot-5, so the box is plenty deep!

garden box flipped over — The 1-by-2s helped keep the box off the deck to prevent rotting.

With the box ready, John and Elly filled it with a mixture of top soil and compost and planted their tomato and herb starts. The photo at right was taken right after planting, and I’ve since heard that the plants are all doing well and the tomatoes have gotten big and already have blossoms. What a great way to raise vegetables in a small space!