Best Liners For Flower Boxes: Coir and Plastic Options

#1 · Best Overall

1. DUNCHATY 24 Inch Trough Coco Liners

• Dimensions D x W x H: 24"D x 7"W x 7"H
• Material: Premium-Coir

Best for: Moisture-conscious troughs.

Why it ranks #1: The two-pack is sized 24 x 7 x 7 inches and is made for window boxes and wall troughs, with coir described as moisture-retaining and porous.

The 24-inch two-pack pairs thick coconut coir with a porous structure intended to retain moisture while promoting air pruning, giving trough gardeners a ready-shaped replacement focused on root conditions. Its stated 24-by-7-by-7-inch dimensions identify the planter profile it is meant to serve.

DUNCHATY says the thick fibers retain moisture, which can help keep soil hydrated between watering, while the porous structure promotes air pruning and is described as preventing root rot. The liners are de-salted and pH neutral for root growth. Setup involves soaking the coir in water to mold it, then filling it with potting soil. The two-piece set is listed for flower boxes, wall troughs, and deck railing planters, supporting a straightforward replacement workflow for compatible outdoor containers.

Skip it if you need a longer 36-inch replacement; HHTHH’s 36-inch pair fits a longer trough format.

Consider this set for 24-inch window boxes, wall troughs, or railing planters where moisture retention and the described air-pruning structure matter. Its 7-inch width and depth and soak-to-mold setup are important fit and installation considerations.

Listed on Amazon as: DUNCHATY 24 Inch Trough Coco Liners for Planters – 2 Pack Window Box Liners

#2 · Best 24-Inch Pair

2. Karlliu 24 Inch Trough Liners

• Dimensions D x W x H: 7.5"D x 24"W x 6.75"H
• Material: Coconut fibre
• Weight: 13.76 oz

Best for: Everyday 24-inch boxes.

Why it ranks #2: Two natural coco-fiber liners measure 24 x 7.5 x 6.75 inches, making this a close-fit option for a 24-inch window box.

Two 24-inch natural coconut-fiber trough liners give window-box owners a ready-made replacement option with breathability and water retention listed as core features. Their 7.5-inch width and 6.75-inch depth help identify the trough profile, while the set suits outdoor flower and leafy-plant use.

Karlliu describes the natural coco fibers as breathable and moisture-retaining, a combination intended to keep soil moist while supporting plant growth. The 24-by-7.5-by-6.75-inch dimensions help shoppers compare the liners with their box before installation. A molded trough shape avoids cutting a roll, and the two-pack supplies a pair of replacements for compatible planters. Listed plant examples include radish greens, ivy, goldfish plants, and leafy or flowering plants, making the intended planting range clear.

Skip it if you need a sheet to trim for several shapes; Sinimaka’s 16-by-40-inch roll can be cut for different containers.

This pair suits gardeners replacing liners in compatible 24-inch window boxes or outdoor troughs for flowers and leafy plants. Check the stated 7.5-inch width and 6.75-inch depth against the planter, since the product is a fixed trough shape.

Listed on Amazon as: 2 Pack 24 Inch Trough Coconut Liners for Window Box Planter Natural Coco Fiber Replacement Liner for Outdoor Plants Flowers Outside Coir Planters Porch Balcony Garden Decor

#3 · Best Size Detail

3. HKZ 24 Inch Trough Coco Liners

• Dimensions D x W x H: 6.7"D x 24"W x 6.7"H
• Material: Natural Coconut Fiber

Best for: Compact 24-inch troughs.

Why it ranks #3: The two-piece set lists each liner at 24 x 6.7 x 6.7 inches and specifically targets window boxes and fence planters under 24 inches.

Two 24-inch trough liners with a stated 6.7-inch width and depth give window-box owners a defined fit for compact railing and fence planters. Their natural coconut fiber has tiny pores for air circulation and drainage, supporting a planted setup without a plastic insert.

HKZ specifies that each liner measures about 24 by 6.7 by 6.7 inches and is tailored for wire baskets under 24 inches, making planter measurement central to a good fit. The natural-fiber material has small pores that provide air circulation and drainage, features relevant to roots and excess water movement. A two-piece pack supplies replacements for a pair of compatible boxes. The product is also listed as weather resistant, supporting its stated use in outdoor fence or railing planters.

Skip it if you need a longer window-box liner; EROCK’s options include 30-, 36-, and 48-inch lengths.

This set suits compact wire baskets and window boxes under 24 inches where airflow and drainage are priorities. Its 6.7-inch width and depth, along with the specified basket-length guidance, make checking the planter dimensions essential.

Listed on Amazon as: Coconut Liner for Planters – 2 Pcs 24 Inch Trough Coco Liners for Window Box, Natural Coconut Coir Fiber Planter Liners for Garden Fence Planter Flower Baskets

#4 · Best Long Box Pair

4. HHTHH 36-Inch Trough Coco Liners

• Dimensions D x W x H: 8"D x 36"W x 8"H
• Material: coconut fiber
• Weight: 16 oz

Best for: Long window boxes.

Why it ranks #4: Two preformed natural coconut-fiber liners measure 36 x 8 x 8 inches, suiting longer and deeper trough-style flower boxes.

The pre-formed 36-inch trough shape gives long window boxes and fence planters a ready-made natural-fiber liner, so you can place the coir in a compatible planter without cutting a sheet. Its 8-inch width and depth suit deeper troughs, while the two-piece set provides liners for more than one planting setup.

Made from 100% natural coconut fiber, each lightweight liner offers a molded shape for a more direct setup than a roll that needs trimming. The stated 36-by-8-by-8-inch dimensions help shoppers assess whether it suits a long trough, and the listed 8-gallon capacity gives a reference for planting volume. Coir is the core material, and the product information suggests adding water-absorbing crystals or perlite when extra moisture retention is needed in hot or windy conditions.

Skip it if you need a cut-to-shape sheet or a short trough; SUNYAY’s 12-by-40-inch roll offers material to trim.

Choose this set for a 36-inch window box, fence trough, or balcony planter where a pre-formed coconut liner saves shaping time. Its 8-inch profile is the key fit consideration, and extra moisture support may help in exposed conditions.

Listed on Amazon as: 2pcs Trough Coco Liner 36 inch Wall Planter Replaceable Coco Liner for Window Box, Fence Flower Baskets

#5

5. EROCK Trough Coco Liners

• Dimensions D x W x H: 24"D x 24"W x 7"H
• Material: Coir
• Weight: 16 oz

Best for: Multiple trough lengths.

Why it ranks #5: The two-piece coir set is offered in 24-, 30-, 36-, and 48-inch sizes for troughs, though its listed dimensions and size description are less clear.

The two-piece set is offered in 24-, 30-, 36-, and 48-inch options, giving window-box and hanging-planter owners several molded coir lengths to choose from. Made from natural coconut fiber, the liners are described as helping soil stay moist while allowing air circulation.

ERock’s molded replacement liners are intended for plant-hanging baskets and trough-style planters, so installation centers on fixing the liner in place before adding flowers or greenery. The available lengths span 24 to 48 inches, which lets buyers select a format suited to different planter runs. Natural coir is described as supporting moisture retention and air circulation, balancing two practical needs for planted containers. The listed two-piece pack supplies a pair at the selected size.

Skip it if you want one sheet to cut into custom shapes; Sinimaka’s 16-by-40-inch roll is intended for trimming.

Choose this set when you want a pair of molded coir replacements and can select one of its listed trough lengths. Match the chosen length to the planter before ordering, as the format is not a customizable sheet.

Listed on Amazon as: 2 Pack Trough Coco Liner Fiber Replacement for Planters, 24/30/36/48 inch Half Moon Coconut Coir Planter for Window Box/Hanging Garden Vegetables Pot, Fence Flower Baskets

#6 · Best Short Box Pair

6. LaLaGreen 16-Inch Rectangular Liners

• Material: Coco Liner

Best for: Small hanging planters.

Why it ranks #6: This two-pack is a pre-shaped rectangular coco liner for a 16-inch planter, with listed dimensions of 15.75 x 6.3 x 4.72 inches.

Two pre-shaped 16-inch rectangular coir liners offer a quick replacement for compatible metal hanging planters, avoiding the need to cut a roll. Their natural coco material is described as breathable, durable, and supportive of drainage and root aeration for outdoor planting.

LaLaGreen says the liners simply insert into the basket, with soaking in water before planting as part of preparation. The pre-shaped rectangular form supports a more direct setup than a loose sheet, while the product identifies a 16-inch metal hanging planter as a suitable application. Natural coco coir is described as providing drainage and aeration for roots. The two-pack supplies a pair of liners, and the listed dimensions—about 15.75 inches long—help buyers assess the intended planter scale.

Skip it if you need a 24-inch trough replacement; Karlliu’s two-pack is listed for 24-inch planters.

Pick this pair for compatible 16-inch metal hanging planters when a pre-shaped coir insert simplifies setup. Soak the liners before planting and consider the listed roughly 15.75-inch length when checking the basket’s interior.

Listed on Amazon as: LaLaGreen 16" (2 Pack, Rectangular) Trough Coco Liners for Planter – Medium Coconut Coir Replacement for Window Box, Wall Mount Flower Pot, Outdoor Use– Also Available in 24/30’’ and Different Shapes

#7

7. Winlyn Clear Plastic Planter Liners

• Dimensions D x W x H: 3"D x 16.2"W x 3.5"H
• Material: Plastic
• Weight: 16 oz

Best for: Water-protective inserts.

Why it ranks #7: Ten clear rectangular plastic inserts measure 16.2 x 3 x 3.5 inches and are intended to protect flower and window boxes from draining water.

Ten clear plastic liners provide a practical alternative to coir when the priority is containing soil and draining water inside a flower box. Each is listed at 16.2 inches long, 3 inches wide, and 3.5 inches high, and the liners can also serve as standalone planters.

The clear plastic construction is described as keeping soil and water safely inside a planter, helping protect the surrounding flower-box material from drainage. The listed drainage hole supports water release, while the rectangular 16.2-by-3-by-3.5-inch profile suits narrow arrangements such as windowsill plantings. Ten pieces make the set useful for multiple containers or seedlings. The material is durable, lightweight, shatterproof, and fade-resistant according to the supplied description, supporting repeated indoor or outdoor planting use.

Skip it if you want a natural coir liner that breathes; SUNYAY’s coconut-fiber roll offers a natural sheet format.

Choose these inserts when protecting a flower box from soil and draining water matters more than using coir. Their narrow rectangular dimensions suit smaller arrangements, so compare the 16.2-inch length and 3-inch width with the planter interior.

Listed on Amazon as: 10 Pcs Plastic Planter Liners Clear Rectangular Plastic Liners for Flower Box Planter Window Box Planter 16.2" L x 3" W x 3.5" H for Indoor Outdoor Flower Arrangement Succulent Garden Windowsill Decor

#8

8. Sinimaka Coco Liner Roll

• Weight: 10.6 oz

Best for: Custom-cut planter projects.

Why it ranks #8: The 16 x 40-inch natural coir sheet can be cut to fit different containers, but requires shaping rather than arriving as a molded flower-box liner.

A 16-by-40-inch cuttable coconut-fiber sheet gives DIY gardeners room to shape a liner around different containers, rather than being limited to one trough size. Its tightly woven, natural coir construction combines shaping flexibility with a sturdy sheet for planter and other listed uses.

The single 16-by-40-inch sheet can be cut to suit various shapes and container sizes, making it useful when standard molded liners do not match a project. Sinimaka describes the natural coconut-husk fibers as tightly woven for sturdiness and biodegradable. Its drainage holes support water movement and air circulation around roots, while the stated water-retention and drainage balance helps explain its intended role as a planting liner. The sheet format does mean measuring and cutting are part of setup.

Skip it if you prefer a fixed-size insert with no trimming; HKZ’s 24-inch two-pack arrives as trough liners.

This sheet suits gardeners adapting liners for nonstandard containers or DIY projects. Its drainage and airflow features support planting use, but buyers seeking a quick drop-in replacement should account for the measuring and cutting required.

Listed on Amazon as: Sinimaka Coco Liner Roll, 16 x 40 Inch Coconut Fiber Liners for Planter Window Box Flower Basket, Natural Coco Coir Sheet Coco Mats for Animal Pet Pad, Reptile Carpet, Garden Decoration

#9

9. SUNYAY 12 x 40-Inch Coco Roll

• Dimensions D x W x H: 12"D x 40"W x 11.81"H
• Material: Coconut fiber
• Weight: 3.04 oz

Best for: DIY liner shaping.

Why it ranks #9: This 12 x 40-inch natural coir sheet is a versatile cut-to-fit liner option, but its width may not suit deeper or wider flower boxes.

The 12-by-40-inch coir roll lets you cut a natural-fiber sheet to suit different planter shapes, rather than relying on a fixed molded trough. That flexibility also supports the listed uses beyond flower boxes, including hanging baskets, pet pads, weed mats, and garden decoration.

SUNYAY supplies the coconut fiber packed as a roll, which makes it possible to measure and trim sections for window boxes or other containers. Its breathable coir construction is listed as aeration- and drainage-hole-friendly, useful when fitting a liner around a planter that needs airflow and drainage. The 12-by-40-inch dimensions define the available sheet area, so buyers can plan cuts for their containers and other stated applications before laying it in place.

Skip it if you want a ready-shaped 24-inch trough; DUNCHATY’s 24-inch two-pack comes as replacement liners.

Pick this roll when one flexible sheet for several planter shapes or garden uses is more useful than a fixed-size insert. Measure your containers and plan the cuts first, since the supplied material is a roll rather than a pre-formed liner.

Listed on Amazon as: SUNYAY 12×40 inch Natural Coco Liner Roll Coconut Coir Liner Sheets Coco Mat for Planter Window Box Flower Basket Garden Decoration Animal Pet Pad

#10

10. Yarrdfir 16 x 120-Inch Coco Mat

• Weight: 1.5 lb

Best for: Large-area liner cutting.

Why it ranks #10: The large 16 x 120-inch coconut-fiber mat can be used for planter DIY, but its broad multipurpose format offers little flower-box fit guidance.

The 16-by-120-inch coconut-fiber mat supplies a long sheet for gardeners who need broad coverage or multiple cut sections, instead of a single molded box liner. Its natural, breathable, lightweight material is also listed for uses such as reptile carpet, pet pads, and garden decoration.

Yarrdfir’s 16-by-120-inch size provides a substantial length of coir mat that can be handled and moved as needed, with the product described as lightweight and durable. The natural coconut fiber is presented as breathable and sustainable, making the sheet relevant to planter lining as well as the listed pet-pad, reptile-carpet, and decorative uses. Because it is a mat rather than a pre-shaped trough, adapting it to a planter requires shaping or cutting to suit the container.

Skip it if you need a molded drop-in trough without trimming; Karlliu’s 24-inch two-pack comes in a fixed trough shape.

This long mat fits gardeners who want generous coir coverage for DIY planter lining or the other listed mat uses. It offers more length than a short sheet, but requires shaping to match a particular flower box.

Listed on Amazon as: Coco Coir Liner, Yarrdfir 16×120 inch Natural Coconut Liners for planters Flower Basket, Natural Coconut Fiber mat, Garden Decoration, Animal pet pad, Reptile Carpet, Snow Mat