How to DIY Window Box Planters in 3 Easy Steps

June 19, 2024

Hi! I'm Nicole

Fearless DIY. Sharing building project tutorials and interior design tips. Let’s build something beautiful together. For more projects, design tips and behind the scenes, follow me @designtobuild.nicole

More About Me



DIY window box planters! The easiest and cheapest way to add curb appeal!

Dog-eared fencing isn’t just for fencing. It’s one of the cheapest outdoor woods you can buy. And often overlooked for implementing it in building projects.

It’s time to think outside the box. I’m going to show you my secret to building the cheapest and easiest flower box. This flower box is sure to last for years and years to come.


A few summers ago, I did a complete makeover on the outside of our house. From limewashing the brick to changing up the exterior colors, our house went through a complete makeover.

2 story home with white brick, gray cedar siding, white trim and black shutters/garage doors

I have always loved our shuttered faux window.

But I could never figure out how to make it pop. Not sure, why I didn’t think of this sooner, but why not add some hardware.….

Amazon Affiliate Link Included

faux window with hardware

And a flower box….

A flower box outside a faux window full of beautiful flowers

This is the perfect project that won’t break the bank, but still brings all the curb appeal.

So let’s get to it…

The Cheapest Way to DIY Window Box Planters

Instructions are based upon one 50″ long; 12″ deep and  6 3/4″ wide flower box

Wood Needed:

Picket fencing strips (6) (amount needed, dependent upon the size of flower box)

Materials Needed:

Tools Needed:

Amazon Affiliate Links Included

Determining the Dimensions of Your Window Box

Before starting on the project, the first thing you’ll want to do is measure the space where you’ll be attaching your flower box. Three things you want to determine are:

  • the length
  • width
  • and depth

Here are some pointers for deciding on each dimension.


Measure the length of the window where you plan to place the box.

For a balanced look, the length of your window planter box should be about the same as the width of your window.

If you want a more dramatic effect, you can make it a bit longer A good rule of thumb is no more than 3 inches wider than the window frame.

It’s also a good idea to avoid making it too short. This can make it look out of proportion.


When referring to the width, we’re talking about the front-to-back measurement.

A standard width for window planter boxes is around 6 to 8 inches. This gives your plants enough room to grow without overcrowding.

If you’re planning on placing your flower box on the window sill, you’ll need to measure the width accordingly.


The depth of the box is crucial for the health of your plants. Most flowers need a depth of at least 6 inches, but 8 to 10 inches is better for a variety of plants.

Check the root depth requirements for the specific plants you plan to use to ensure they will thrive.

Additional Tips

  • Ensure there are drainage holes at the bottom of the box to prevent water-logging.
  • Consider the weight of the box when filled with soil and plants, especially if it will be mounted on a wall or window frame. We’ll talk more about this in just a bit.
  • Make sure the box is easily accessible for watering and maintenance.

Measure space and cut 4 boards to the length you need (in my case, 50″).

Step One: Make Cuts and Drill

Now that we have our measurements, we’re ready to start making our new window box.

For our first step, we’re going to cut four boards to the length we decided on above. Cut your boards, using a miter saw or circular saw.

Side Note: For this tutorial, I’m going to refer to the measurements of my window box.

Using a Kreg Jig, drill pocket holes along one long edge of 2 of your 4 boards.

Then use 1″ pocket hole screws to attach the two boards. This will be the inside of your front window box boards….

two cedar boards pocket holed together

Do the same for the back boards of your flower box. You should now have TWO sections that look like the picture above.

NOTE: Only one section is shown above, but you should have two sections now.

For the bottom piece of our window box, we’ll use one cedar board (dog ear fencing).

If you plan on making your window box wider be sure to add a new board, using the same steps as we used to build the front and back.

In the picture below, we now have our front, back, and bottom (just one picket fence board) for our flower box…

4 cedar boards pocket holed together

Step Two: Assemble DIY Window Planter Box

Using wood screws, you’re now ready to drill your front and back board into your bottom board.

Make sure the pocket holes are on the inside, so as not to be seen…

front and back of flower box built

These are my favorite screws to use for all of my projects

Amazon Affiliate Link Included

GRK screws with flower box being built

Step Three: Add the End Pieces

Next step, cut your end pieces to fit.

Attach each end piece board, using wood screws.

You’ll drill them in from the sides, as shown in the picture below…

side of box being built

And that’s it!! Such an easy DIY project!

Now, your easy DIY window box planter should look like this…

front, back and sides of flower box built with cedar

Finishing Touches

Before attaching the flower box to the exterior of your home, you’ll want to add the finishing touches.

I chose to paint my window box black to coordinate well with the paint colors of my home.

You can choose any color paint or stain you desire. It does not have to be an exterior paint.

However, you will want to give it a couple coats of exterior primer to protect the paint or stain from the elements.

flower box painted black

How to Attach a Window Box

Now you’re ready to attach your window box. Depending on the exterior material of your home, here are 3 different ways…

How to Attach a Window Box to Vinyl

Attaching a window box to vinyl siding is straightforward if you follow these steps:

  1. Locate the Studs: Use a stud finder to locate the studs behind the vinyl siding. Mark these spots, as they will provide a more secure attachment point.
  2. Drill Pilot Holes: Using a 1/8-inch drill bit, drill pilot holes through the vinyl siding into the studs. This will make it easier to insert the screws and prevent the vinyl from cracking.
  3. Attach Mounting Brackets: Align the back of the box with the pilot holes. Securely attach the mounting brackets using screws. Make sure the brackets are level before fully tightening the screws.
  4. Mount the Window Box: Once the brackets are in place, hang the window box onto the brackets. Double-check that the box is level and secure.

Hanging a Window Box on Brick

  1. Mark the Position: Determine where you want to place the window box on the brick wall. Mark the spots where you will drill holes for securing the box.
  2. Drill Pilot Holes: Use a masonry bit to drill pilot holes into the brick at the marked spots. A 1/4-inch drill bit is usually sufficient. Drill into the mortar joints for a more secure hold.
  3. Insert Anchors: Place masonry anchors into the pilot holes. These will hold the screws securely in the brick.
  4. Prepare the Box: On the back of the box, mark the spots where the screws will go. Ensure these marks align with the pilot holes in the brick.
  5. Secure the Box: Hold the window box against the brick wall, aligning the marks with the anchors. Using weather-resistant screws, attach the box directly to the wall through the anchors.
  6. Check Stability: Ensure the box is level and securely fastened. Double-check for any movement and tighten screws as needed.

How to Attach a Window Box to Cedar Siding

Cedar siding is relatively easy to work with, but you’ll still need to ensure a secure attachment:

  1. Find the Studs: Use a stud finder to locate the studs behind the cedar siding. Mark these locations for drilling.
  2. Drill Pilot Holes: Using a 1/8-inch drill bit, drill pilot holes into the cedar siding at the marked spots. This step helps prevent the wood from splitting.
  3. Install Mounting Brackets: Align the back of the box with the pilot holes and attach the mounting brackets using screws. Make sure the brackets are level before fully tightening the screws.
  4. Mount the Window Box: Once the brackets are installed, hang the window box onto them. Ensure the box is level and securely attached to the side of your house.

Final Tips

  • Always check that the window box is level before completing the installation.
  • Use weather-resistant screws and brackets to ensure longevity.
  • For added stability, consider using multiple brackets, especially for larger or heavier boxes.

By following these steps, you can easily attach a window box to vinyl siding, brick, or cedar siding, ensuring a secure and attractive addition to your home.

And now you’re ready for the pretty part. Add dirt and beautiful flowers. And watch them thrive all summer long…

A beautiful wooden flower box full of pink and white flowers

So good!

Flower box with pink and white flowers on a white brick house

Isn’t it amazing what a flower box will do to enhance the curb appeal of your home?

Front door of a white brick house with white flowers all around it

DIY window boxes are a great way to add color and visual interest to any home…

American Flag, flower box with pink flowers, Faux window, limewashed brick

Best Place to Put a Window Box

The best place to put a window box is under a double or single window that gets plenty of sunlight.

Window planters are a great way to add color and charm to your home’s exterior.

While personal preference plays a role, placing them under kitchen or living room windows can provide a pleasant view and easy access for watering and maintenance.

What to Plant In a Window Box

For a vibrant display, plant colorful flowers like petunias, geraniums, and marigolds. Mix in trailing plants such as sweet potato vine for added texture.

Add foliage plants like coleus or dusty miller to provide contrast and depth. This combination will create a stunning, eye-catching window box.

Let’s go beyond the design to build something beautiful together!

Until next time,

Happy Building, Friend!!

Be sure to join my VIP List below and never miss an upcoming post.

Want to know what I’m working on now? Come check out my latest project in real time over on Instagram. See you there!!

Three more great outdoor posts:

How to Limewash Brick Exterior

How to Build Board and Batten Craftsman Shutters

The Craftsman Garage Doors-Get the Look Without all the Costs

Read more posts like this one…

What To Consider When Installing a Deck for Your Home

What To Consider When Installing a Deck for Your Home

Are you the kind of person who likes to spend all their summer hours outside with friends and family? Or maybe you’re just someone who wants to be out enjoying the weather before the cold months of winter hit. If so, you may want to consider the benefits of installing...

Murphy Bed Benefits: Combining a Home Office and Guest Room

Murphy Bed Benefits: Combining a Home Office and Guest Room

Navigating the challenge of combining a cozy guest room with a functional home office seemed daunting until I partnered with Create-A-Bed. Their innovative Murphy bed solutions transformed my space. Showcasing key Murphy bed benefits such as style and practicality...



  1. Oh Christmas Tree! Holiday Home Tour 2021 - Repurpose Life - […] this window box and faux window black this summer, was a good move. I love how the fresh boughs,…

Submit a Comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.