A DIY Window Box With a Patriotic Feel

Elena K, Hometalk Team
by Elena K, Hometalk Team
14 Materials
3-5 Hours
Ever since we moved to our old house nine years ago, I dreamed of having window boxes. But with always so-much-to-do and ongoing home-improvement projects, my window boxes were always put on the back burner.
With our little yard almost done (except for a trellis--that will be coming next week), it's time to tackle a DIY a custom-sized window box.
Absolutely LOVE my new window box!
Stay with me to learn how to make yours!
Materials you'll need to make yours

(1-2) 5/8" x 6"x 8' dried cedar lumber

T-square or Tape measure


Power saw or hand saw

Nail Gun or Hammer

1" - 1 1/4" galvanized finish nails

Drill or Hammer Drill

9'16" - 3/4" spade drill bit

Wood glue

Mask - recommended

Goggles - recommended

Sandpaper or sanding sponge (optional)

Paint or stain (optional)

Brush or foam paint sponge (optional)

NOTE: You may notice the dimensions (width & length) of your panel are smaller than those specified by the manufacturer-I was told at the Home Center that this is usually the case. In any case, I'm going to use standard lumber size here as a reference.

To make a rectangular box, you'll need to cut 2 long sides (front and back), a base (shorter than the long sides) plus 2 short sides.

My window is wide, so I'm going to make my box a standard 36" - you can go with anything you like, or a 30" standard.

TIP: Box should be smaller than window, to have a few extra inches on either side, so plants can grow.

To make a 36" wide window box I'll need:

- 2 panels of 36" long (front and back)

- 1 panel of 34 5/8" long (base)

- 2 square panels of 6" x 6" (sides). Or whatever the panel width is: turned out the standard manufacturer 6" width was in fact, more like 5 5/8"

If my window were 30" instead of 36", I'd need: 2 panels 30" (sides), 1 panel 28 5/8" (base), and 2 panels 6" x 6" (sides)

You get the idea, right?

TIP: Before you cut, make sure your wood is well dried.

I got treated cedar wood, which was still moist, so I laid it on the floor for a few days before I started with this project to let it dry.
Ready? Let's start with the front panel!

Get the wood, the T-square and a pencil and measure the longer side of the planter: that is 36" for me. (Yours can be 30" or something else.)

TIP: to the 36" add an extra 1/8" to account for the blade, because if you cut right on your 36" mark you'll end up with a shorter piece (of about 35 7/8").
Time to cut the front panel!

Place your plank in the saw bed and cut.

Now that we have the first side, we'll have to cut another one of this size. At this point, forget about the ruler! We're going to use the piece we just cut to measure.
The other long panel is next!

I use a little trick that makes it easier: overlap the piece already cut over the remaining plank, and trace the end with the pencil.

TIP: Don't forget to add that extra 1/8" to account for the blade. Then go ahead and cut.

That makes 2 (36") panels for the long sides.
Time to tackle the base and sides!

For the base, instead of measuring, I use the ruler to mark the amount that I need to subtract (i.e. 2 panels thickness or 1 3/8") and then transfer that to my base panel.

In any case, your base needs to be 1 3/8" shorter than your sides: in my window that is 34 5/8".

Makes sense?

Finally I'm going to cut 2 small pieces that will be the "legs," so you can put it directly on a windowsill. Mine were 4/4"-1" wide x 5 5/8". (You can make them a little narrower than the base, I kept them the same width.)

We still need to cut 2 short square pieces to close the box.

These will be 6" x 6" each, or whatever width your lumber is. (As I mentioned earlier, mine turned out 5 5/8" instead of the 6" the manufacturer claimed - so my sides are 5 5/8" square.)

So, go ahead, measure and cut.
Next: make drain holes & add legs to the base

Now that I have all the parts cut, I need to finish the base before assembling.

First: Place the base in your table. Use the T square to draw the center lengthwise, and make two marks, centered, at about 5"-7" off each edge.

TIP: I like to make a cross to indicate where the drill bit will go.

Get your drill-I have a hammer drill but a simple drill will make, we don't need much power here!-and a spade drill bit.

Remember: the larger the bite the bigger the drain hole. Since I'm going to make two, a 9/16" is enough for me.

TIP: Clamp your base so it doesn't wiggle on the table while you're drilling and nailing.

Then drill both holes all the way through.

Put your drill away: we're done with it!
Moving along: Let's nail the legs next!

With the base still clamped, place the legs about 1.5" - 2" off the drain holes.

Get your nails and hammer or nail gun ready, because we're going to nail the legs next. Starting about 1" off the edge, put 3 or 4 nails on each leg evenly spread. No need to measure, you can eye ball where nails should go.

Go ahead and start nailing.

Then, remove clamps and let's get everything ready to assemble the box!
Next: Get your tools ready.

Get the panels and tools ready. Besides the (5) box pieces, we'll also need wood glue-Elmers Wood, Gorilla Wood or Titebond III (my favorite)-a hammer or nail gun, and galvanized nails: ideally 1/4" long

Now that we have all the parts ready, let's put the box together!
Yes! We're finally ready to assemble.

Let's start by assembling a 36" long side to the base. The base is shorter than the side (remember?), so I centered the 36" within the base.

First, put a bead of glue on the long edge of the base. Then, nail the long (36") panel.

My first nail goes close to the edge, about 3/4"-1" off. Next, I do another nail in the middle, and a third one close to the opposite end.

Then, I add a few more in between, leaving about 1"-15" in between each nail.

Once you're done nailing that side, don't forget to clean the dripping glue both in and out.

TIP: If your nails are too close to the ends, they may split the wood. That's why leaving a 3/4" margin makes sense.

TIP: Use a damp cloth to remove excess glue, so the stain (or paint) adheres better.

Turn the L shape you got by nailing side to base, and repeat step: glue and nail the other 36" long side to the base.

Finally, glue /nail the two short side sides to close the box.

TIP: Don't forget to add the glue before you nail, and to clean the drips after with a damp cloth.

Time to call it a day! Before we move on, we need to let that glue dry well for at least 24 hours.
Are you ready? Time to make it look real nice
STEP 10 (Optional): PAINT or STAIN BOX

Feel free to sand the edges to get a smoother feel. To do so, you can use a sanding sponge or a (random orbital or belt) sander. To sand, start with a coarse grit 40 - 60, and then use a finer 180-220 to get that super smooth finish.

Since I'll be staining my box, I'm going to skip this step. The darker color will mask the imperfections.

To paint or stain, I need gloves, a mask, a sponge brush or brush, and stain or paint.

TIP: Apply the stain outside or with doors or windows open: the fumes are strong and can be toxic! And don't forget to wear the mask. Getting a "green" non-VOC stain or paint is the way to go.

I'm using a minwax mahogany, but you can do any color you like.

TIP: Since we'll have soil inside the box, there's no need to stain or paint the interior.

One coat was enough for me, but you may need to apply 2-especially if you're using paint instead of stain.

TIP: If you're painting the window box, make sure you use an exterior paint that works on wood. (Some exterior are just formulated for metal.)
Let's add the lining and wrap this up!
To avoid the soil spilling out, you can use a black lining fabric or burlap to cover the drain holes.

I'm doing black lining--I have a ton left over from another project!)--and will double the fabric because it's really thin.

TIP: No need to measure, just eye ball the size. If it's too large, you can always fold it in and tuck it in under the soil
Get the soil ready, a trowel and fill it in!

To keep the fabric in place, I can staple the sides. But instead, I'll just use tape to temporarily hold it until I fill it with soil. It's easier and I need less tools!

Feel free to staple yours for a neater finish.

Now, get a trowel and fill the box with soil. I'm using manure, but any good organic soil, or compost will make.
Get your plants ready and let's do it!

If you've read my other posts, you've noticed I like to plan, plan, plan.

So I'm going to layout out my flowers next to the window box to get a layout I like.

Keeping up with my July 4th preparations, I'm making a patriotic planter: flowers need to be blue, red, and white. Combining petunias with geraniums is perfect.

I'm alternating colors, shapes, and also different heights, all while leaving enough room to grow throughout summer. Petunias are shorter and will spread low while geraniums will grow a little taller and fuller.

But of course, you can plant your favorite flowers-or herbs-here.

Can't wait to see it finished!
It's done! Love color punch it brings in.

Move your box to window and Enjoy!

If your windowsill is not deep enough, you'll need to hang it. There are several ways of installing a window box, and plenty of info at http://www.thisoldhouse.com/, http://www.askthebuilder.com as well as youtube.

Make sure you get the appropriate brackets and screws for your wall (is your house brick or shingles?) and that they have the correct length.

TIP: Lastly, if you need to drill holes to attach the box to the brackets, do so during the assembling - before you fill it with soil and plant the flowers.

In any case, hope you give it a try.

And if you enjoyed making the box, check my other post on how to make a small DYI hanging box with pallet wood. It'd be the perfect complement to your window box!


And for How to Make a Patriotic Wreath (with your old jeans!) to complete your 4th of July decor, go here: http://www.hometalk.com/diy/craft/holiday-crafts/make-a-patriotic-wreath-with-your-old-jeans--17278159
Suggested materials:
  • (1-2) 5/8" x 6"x 8' dried cedar lumber   (Home Center)
  • T-square or Tape measure   (Home Center)
  • Pencil   (Craft Store)
See all materials
Frequently asked questions
Have a question about this project?
  1 question
  • Charly Charly on Apr 30, 2017
    Your list of materials calls for wood that is 5/8 by 6 inches eight feet. Shouldn't it be 6'8"?

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