Heavy Duty Poly-Pro Window Box Liners 3 Colors

Made in USA in these sizes:

• 17.5" L x 8"W x 5"H 
• 23.5" L x 8"W x 5"H 
• 29.75"L x 8"W x 5"H
• 35.75"L x 8"W x 5"H

Get more from your window boxes and planters with these simple and functional liners. Originally only offered in black, we now offer our standard plastic liners in white and green. They're inherently colored, so there is no concern of the finish ever chipping off. Since darker colors absorb more UV rays and conduct more heat, green and black plastic liners are a great choice for starting seedlings. Our classic white color reflects the sun's rays and is great for sunny areas, and in locations where the liner will be seen.

There are many perks to using a liner with your coordinating window boxes. They're easy to remove, which makes cleaning, replanting, or switching out seasonal faux flowers quicker and easier. It also makes it possible to move flowers from one setting to another in order to ensure every arrangement gets its fair share of time in the sun, or to take plants indoors when the weather turns unexpectedly colder than anticipated. Additionally, their spacious interior has plenty of room for any plant life you have in mind. From herbs outside the kitchen window or lush flowers that bloom for all to see, your gardening options have opened up wider than ever before.

These polypropylene (poly-pro) liners are made from highly durable plastic materials that won't rot or warp like wooden liners and boxes can, so you can rest assured they'll hold up against wear and tear, even when used in inclement outdoor conditions.

Drop them in existing planters, or use them as standalone garden boxes. Place atop dividing walls, or mount along railings and building exteriors (purchase additional brackets). These liners are not available in custom sizes, but we do manufacture custom liners in other materials. Shop online or call toll-free to discuss your options: 1-800-896-0978

FAQs

What color should I choose for my window box liners?

It depends on the setting and what you're growing. White reflects sunlight beautifully and looks polished in spots where the liner peeks through, while green and black absorb warmth, making them ideal for starting seedlings or tucking discreetly behind lush blooms. All three shades are solid through and through, so the color never chips or fades.

Where can I find a liner that creates drainage for outdoor planting?

Each of our liners comes with pre-scored circles at the base that you can easily knock out when you want outdoor drainage. Leave them intact for a watertight fit indoors, or open them up for garden use. This flexibility means one liner adapts to however you're planting that season.

How do I know which size fits my existing window box?

These liners are made in the sizes shown on the product page, so measure the interior length of your window box or planter and match it to the closest listed option. They're designed to slide neatly into standard-size boxes, giving you a tidy, finished look without any gaps.

Why choose a poly-pro liner over a wood insert?

Polypropylene holds its shape season after season without rotting or warping, unlike wood liners exposed to rain and sun. It keeps your window boxes looking fresh year-round while giving you the freedom to swap plantings or take arrangements indoors whenever you like.

Can I use these liners without a window box at all?

You can. Many customers place them directly atop dividing walls, mount them along railings, or use them as standalone garden boxes with additional brackets. This makes them a versatile way to add greenery to spaces that don't have a traditional window box mounted yet. Shop the collection to find your fit.