How To Make A Flower Box

Kirsten|Kirsten

"These Victorian-era flower boxes look so beautiful and professional without requiring insane carpentry skills!"

- Kirsten Dunn



I know a little theater company called Anderlin Arts that performs out of Everett. They're dear friends of mine and people I've had the pleasure of working with on a number of occasions. Coming up the first week of April they're performing a version of The Importance of Being Earnest and asked us to help them out with part of their set. These Victorian-era flower boxes look so beautiful and professional without requiring insane carpentry skills, so I just couldn't say no.

P.S. I'm not in the play (just on the poster). It's going to be a great show, so don't miss it!

Step 1

The first step is to pick out your wood. This will depend on the look you're going for, and whether or not you'll be painting. We chose less expensive construction-grade lumber that we'll be painting over. Due to a time crunch, we built it first and then sent it to the theater to prime and paint before the show, but we recommend painting before assembly and doing a top coat—or just some touch ups—when you're all finished.

If you prefer the look of raw wood, cedar is a wonderful option because it's naturally rot-resistant and has a beautiful, classic look to it.

Step 2

flower box plan

Once you have your lumber, it's time to make cuts. You can do this with a circular saw or with a chop saw like we used. Refer to the cutting diagram above to make your cuts. You'll need to:

Cut the 4x4 into four 19” pieces.

Cut the 2x4s into four 38.5” pieces, four 10.5” pieces, and three 11.5” pieces.

Cut the 1x4s into twenty-eight 15” pieces.

Cut the 1x2s into four 38.5” pieces, and four 10.5” pieces.

Any heavy sanding should happen at this point in the project. We just used a piece of sandpaper to smooth off the cut edges as we went along.

sawing wood for flower box

Step 2

To begin assembly we're going to use a kreg Jig in all the frame pieces. Although not necessary, a kreg jig is a great DIY tool that can make tricky angles more manageable and lend a professional look to your final project. Set the depth to 1 1/2" and drill two holes in both ends of all the 2x4 pieces.

kreg jig for flower box

Step 3

Using a combination square mark where the 2x4s will attach to the 4x4 posts. You'll be making the frame of a box with the 10.5" pieces and the 38.5" pieces.

Measure down from the top of the post 3/4", and up from the bottom 3" and draw lines. Measure 1 1/2" from the side and mark. The 2x4s will sit behind these lines. This way, when you add the 1x4 slats and the 1x2 trim pieces to the outside, the 1x2s will be flush with the posts.

Mark all posts on two sides, keeping in mind which sides of the post will be on the outside of the box.

measuring flower box

Step 4

Begin by attaching two of the 10.5" pieces to the top and bottom of one of the posts using 6" long drill bit from the kreg jig kit and securing it with 2 1/2" screws. Hold firmly in place and screw slowly, or clamp down to keep from slipping. Turn upside down and attach the opposite side of the 2x4s to the next post. Repeat with opposite end of the frame.

Once the short ends are attached, secure the four long 38.5" pieces to one of the ends in the same manner as before. An extra set of hands for holding the boards in place is very helpful for this step.

posts for flower box

Step 5

Next attach the 11.5" supporting slats to the frame. These slats will help keep the plywood from sagging under the weight of plants and soil. It's important that these slats are the right length, so place the end piece of the frame and make sure everything lines up like it should. Trim pieces as needed. Secure slats every 12 inches or so. Clamp in place to make screwing easier.

assembling flower box

Step 6

Next it's time for the plywood bottom piece. We've provided a cutting diagram for this piece, but double-check all your measurements against the frame you just built. With a circular saw, cut the plywood down to 42.5”x14.5” (or to the new measurements you've taken).

plywood for flower box
saw for flower box

Step 7

To fit around the posts in the flower box, notch out 2” corners with a jigsaw. (If you don't have a jigsaw you can get away with using a circular saw). Fit the plywood into the frame and make any necessary adjustments.

measuring for flower box
jigsaw for flower box

Step 8

With the box on its end, fit the plywood bottom in and secure the end of the frame to the 2x4 sides. This may require some manipulation of the 2x4s to line them up with the pencil marks. Again, someone helping makes this step a lot easier.

secure plywood to bottom of box

Step 9

Next, it's time to line up the 1x4 slats on the side of the flower box. The top of the slats should line up with the posts. Use a straight edge, or a scrap piece of wood that's nice and straight to line up the top of the slats with the top of the posts on either corner. Hold slats in place. Predrill with a 3/32" drill bit; two holes at the top of the slat and two at the bottom. You'll want to hide the screws behind the 1x2s you'll be laying down, so predrill approximately 2" from the top and 1 1/2" from the bottom. Secure with 1 1/4" screws.

drill flower box
screws for flower box

Step 10

It's now time to attach the trim boards on the front and sides of the box. Makes sure they fit in place and adjust as necessary. For this board, we used cedar 1x2s. We chose cedar because it has a cleaner edge and is a little higher quality than the construction grade SPF 1x2s. The cedar is also a little rough, so we first sanded it smooth.

Mark on the slats where you want to place the trim boards. We positioned ours 1 1/2" from the top and 1" from the bottom. Secure with glue and finish nails. Be careful to avoid the screws underneath. Nailing in the center of each board will keep that from being an issue. To prevent splitting, pre-drill nail holes with a 1/16" drill bit. But be careful! This bit is very easy to break.

sanding flower box
gluing flower box
hammering flower box

Step 11

The last step is to attach the final post caps. Mark the center of the posts with a combination square or a tape measure. Drill holes with a 7/32" drill bit, and screw on your post caps. You can also use this bit to drill holes in the bottom of the planter for drainage.

post caps for flower box
post caps for box

Step 12

Finish your flower box with that last coat of paint, some exterior stain, or a wood protective like Lifetime Wood Treatment.

Fill with dirt and flowers, and enjoy your beautiful new creation!

flower planter box
diy flower planter box