DIY Window Boxes & How To Attach To Bricks

These DIY window boxes are a great way to add year-round curb appeal to your house. I decided to design and build my own after I was unable to find premade window boxes that I loved. The main issue I had with premade window boxes is that most of them are way too small. I wanted mine to look more substantial and proportional to the size of the windows. I also wanted the front of the window boxes to be slightly angled to create a more custom look. I’m so glad I decided to make my own because I love how they turned out!

During the summer, window boxes look beautiful filled with flowers and vines, or even ornamental grasses. There are so many choices at the nursery in the spring that it can be hard to decide! One year I went with cascading pink petunias that looked great all summer long. They can also look great during the winter – I like to fill mine with mixed evergreen branches and strings of solar lights.

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Building the Window Boxes

The finished window box pictured here is 52” long. I decided to make the window box extend 2” longer than the window on each side.

For durability, I chose to use pressure-treated wood. Because of the chemicals used to treat the wood, these window boxes are not suitable for edible plants or herbs. To avoid this issue you can use rot-resistant cedar wood, although it’s a lot more expensive.

Supplies Needed (to make 52″ long window box):

-Two 1″x4″s (10′ long each), pressure treated
-One 1″x6″ (6′ long), pressure treated
-1″x2″ (around 3′ long to make braces, or any scrap wood you already have)
–Exterior wood glue
–Exterior wood screws
-Smaller wood screws to attach braces inside of window box
-Desired stain/sealer (I used a deck stain- Olympic Elite Woodland Oil in Canyon Brown).

Directions:

1. Cut the 1”x4” boards into 52” pieces (gives you four pieces, each 52” long). These will make up the back and the front of the window box.
2. Cut the 1”x6” board to 52”, you will have a 20” piece remaining. These will make up the bottom and the sides of the window box.
3. Cut your 1”x2” into eight pieces that are about 4” long to make the braces. These add extra strength to the window box and prevent the boards from warping and separating once they’re filled with soil.
4. Using a table saw, cut the edges of the two front 1″x4″ boards with the blade tilted 15°. In the picture below I’ve marked which boards you need to cut on an angle to create this look. (You can skip this step entirely if you want a square front instead of an angled one).
5. Using wood screws and exterior wood glue, assemble the back of the box with two of the 1”x4”s and four of the 1”x2” braces. Make sure your screws are short enough that they don’t go through the other side!
6. Repeat this process for the front of the window box and your angled 1”x4”s.
7. Create the end of your window box using the remaining 20” piece of 1”x6”. Use a miter saw with the blade rotated 15° to cut this piece in half on an angle to create the two end pieces. Measure the length needed at the bottom (see the yellow line in the picture below), and cut the 90° angle accordingly.
8. Now you can assemble the back, bottom, sides and front of the window box together using exterior wood screws. I think I may have used 1-½” or 2” screws.
9. Lastly, drill a few drainage holes in the bottom of the window box using a large drill bit.

Staining the Window Boxes

After the window boxes were completely assembled, I stained them using an exterior one-step stain/sealer. I used Olympic Elite Woodland Oil in Canyon Brown. I also used this stain/sealer on a pergola and on these DIY Garden Posts for string lights that are fully exposed to the elements and the color has held up extremely well over the past three years. I haven’t noticed any fading at all even though the window boxes are on a south-facing wall.

How to Attach Window Boxes to Bricks

Supplies needed:
–Hammer drill (an ordinary drill won’t work nearly as quickly)
–Concrete anchors
-Masonry drill bit (may be included with concrete anchors)
-Large washers
-L-shaped metal brackets
-Wood screws (to attach bottom of window box to brackets)

To attach these DIY Window Boxes to the brick wall, my dad used a hammer drill with a masonry drill bit. We borrowed a hammer drill from a friend, but you can actually rent one from some Home Depot stores.

Then, we used the Tapcon Concrete Anchors to attach the brackets to the house (make sure they’re level!). The packaging will tell you exactly which masonry drill bit you will need, or it might actually be included.

After we attached the brackets to the house, we set the window box on the brackets and attached the underside of the window box to the bottom of the brackets using wood screws.

For extra support, we also attached a couple more tapcon screws (with washers) through the back of the window box directly to the house.

We used washers because we were concerned about the weight of the filled window boxes creating too much pressure on the screw heads attaching the back of the window boxes to the house. The large washers help to distribute the weight/force over a much larger area.

What do you think of these DIY window boxes? Do you have any favorite plants for window boxes? Leave a comment below!