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Building Flower Window Boxes: A Quick Guide For DIY Enthusiasts

Imagine transforming your windows into vibrant bursts of color with overflowing blooms. Window boxes, those charming containers adorning windowsills, are not just aesthetically pleasing, but also offer a plethora of benefits.

From adding a touch of life to your home's exterior to attracting cheerful pollinators like butterflies and bees, window boxes can revitalize any space.

Whether you're a seasoned gardener or just starting out, this guide will equip you with the knowledge and practical steps to create your own stunning window boxes. 

flower window boxes with hydrangea

Choosing the Right Window Box

Selecting the perfect window box is the first step to creating a flourishing display. Here are some key factors to consider: 

  • Size: Window boxes come in various lengths, depths, and widths. Consider the size of your window and the desired visual impact. Larger boxes offer more planting space, while smaller ones might be better suited for limited areas.

  • Material: Popular choices include wood (classic and customizable), cedar (naturally rot-resistant), and vinyl (lightweight and low-maintenance). Wood requires painting or staining for weatherproofing, while cedar offers a natural aesthetic without needing additional treatment. Vinyl is a low-maintenance option but might not offer the same visual warmth as wood or cedar.

  • Drainage: Proper drainage is crucial for healthy plants. Ensure your chosen window box has drainage holes to prevent waterlogging. Some pre-made boxes might come with an elevated base that allows for air circulation and drainage.

Self watering window boxes can be a great option for those who might forget to water regularly. These innovative boxes feature a built-in reservoir that holds water and a wicking system that draws moisture up into the soil as needed.

This ensures consistent hydration for your plants and minimizes the risk of overwatering. While initially more expensive than traditional window boxes, self-watering options offer convenience and peace of mind for busy gardeners.

flower window boxes

Materials and Tools

When diving into the project of building your flower window boxes, having the right materials and tools at your disposal is crucial for a smooth process and successful outcome. Below is a detailed list of essentials you'll need to kickstart your DIY venture: 

  • Lumber: Choose a durable type suited for outdoor use, such as cedar or redwood, to construct the box frame.

  • Screws: Opt for exterior-grade screws to ensure your box withstands weather conditions.

  • Drill: A power drill will be indispensable for efficiently assembling the pieces.

  • Paint or Stain: Consider a weather-resistant option if you plan to add a splash of color or protect the wood.

  • Liner: A sturdy liner will help retain soil and moisture, critical for plant health.

  • Potting Mix: Select a high-quality mix to provide your plants with the nutrients they need to thrive.

Depending on the design complexity and personal touches you wish to add, a few additional tools might come in handy: 

  • Saw: If your lumber isn't pre-cut, a saw will be necessary to size your pieces correctly.

  • Sandpaper: Smooth out any rough edges to give your window box a polished look and feel.

  • Measuring Tape: Precision is key, so a measuring tape will ensure your cuts are accurate.

  • Level: To guarantee your window box hangs straight, a level will be your best ally.

The quality of your materials can greatly influence the durability and appearance of your finished window box, so choose wisely.

flower window boxes

Building the Window Box 

Creating a wooden window box from scratch can be a rewarding project for DIY enthusiasts. Here's a straightforward guide to crafting your own window box:  

  1. Measure and Cut: Start by measuring the window where you plan to hang the box. This ensures your window box fits perfectly. Cut your lumber according to these dimensions. For a standard window box, you might need two long pieces for the front and back, and two shorter pieces for the sides. 

  2. Drill Drainage Holes: Before assembling, drill a few holes in the bottom piece of your lumber. These holes are crucial for water drainage, preventing overwatering and root rot in your plants. 

  3. Assemble the Box: Using screws, attach the side pieces to the ends of the front and back pieces. Ensure the structure is sturdy. Then, fix the bottom piece in place, aligning it with the drilled holes at the bottom. 

  4. Finishing Touches: If desired, you can sand the edges for a smoother finish and apply paint or a protective sealant. This step is optional but recommended to extend the life of your window box. 

For those who prefer a quicker solution or aren't keen on building from scratch, purchasing a pre-made window box is a convenient alternative. Many garden centers and online retailers offer a variety of styles and materials, from rustic wooden boxes to modern metal options.

When choosing a pre-made box, consider the material's durability and how well it complements your home's exterior.

flower window boxes

Planting Your Flowers

Selecting the right flowers is the heart and soul of your window box. To create a thriving, visually captivating display, consider the following factors:

  • Sunlight Exposure: Observe the amount of sunlight your window receives throughout the day. Sun-loving flowers like petunias, marigolds, and geraniums will flourish in full-sun locations, while impatiens, begonias, and fuchsias prefer partial shade.

  • Planting Arrangement: Plan your layout for visual harmony and healthy plant growth. Taller varieties, like trailing plants or small shrubs, can be placed in the back, followed by medium-height flowering plants in the center. Cascading vines or low-growing blooms can fill the front, creating a layered and visually appealing composition.

  • Spacing: Resist the urge to overcrowd your window box. Each plant needs adequate space to grow and receive sufficient sunlight and air circulation. Refer to the plant's individual spacing requirements on the label and avoid cramming them together.

By carefully considering these factors, you can create a vibrant and thriving masterpiece in your window box. Remember, experimentation and personal preference play a key role, so don't be afraid to get creative with your DIY window boxes!


Jenny Kakoudakis

Jenny Kakoudakis likes to blog about gardening. She launched the award-winning Seasons in Colour in 2014. When she is not chasing criminals out of the financial system (her day job), she loves pottering around her own garden.

Read about her garden tips here.



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