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How To Line A Planter Box [And Should You]

Having a liner for your planters separates the soil and water from it. But is it necessary to put a lining in them? If yes, how? Here is what we learned after researching this subject for you.

If your planter box is built of wood, you must line it. You can follow these steps to line a wooden planter:

  1. Spray the planter's surface with a 1:9 mixture of chlorine bleach and water solution. Use the plastic dish scrubber to clean the planter, then let it air dry thoroughly.
  2. Apply a non-toxic, plant-safe waterproofing solution to the planter's surface area. Dry the planter completely.
  3. If the planter's bottom doesn't already have drainage holes, drill some. A medium-sized wood planter with three or four 1/4-inch holes, or one or two bigger holes, drains extra water out of the container.
  4. Completely line the planter with a plastic sheet; it should be cut to reach the rim but stay below it.
  5. Staple the liner around the rim. To allow the extra water to drain out of the plastic liner, pierce the drainage holes with a screwdriver or other pointed object.
  6. Cover the entire bottom of the pot with a layer of plastic or metal screen cloth to keep drainage holes open. Alternately, cover the gaps with shards of shattered pottery or flowerpots.
  7. Place your planter on flat stones, planter feet that are readily accessible, or other items that raise the wood off the deck, porch rail, or ground level.

Read on to learn more about the advantages of lining your planters and the best planter and liner materials to use. We'll also discuss the importance of lining wooden planters and some advice for growing plants in wooden containers. Without further ado, let's dive in!

Row of raised flower planters with lining, How To Line A Planter Box [And Should You]

Why Do You Need To Line A Wooden Planter Box?

A liner is the most effective way to stop deck planters from decaying. A wood planter's lining shields the wood from such elements.

Additionally, leaching is the main disadvantage of using your planter for food, but having liners allow you to grow edibles because they stop the seeping of wood treatment chemicals into the soil.

Instead of lining the planter with dirt and filling it with plants, some gardeners speed up the preparation of wooden planters by trying to fill them with plants in plastic pots.

With this method, you may quickly switch plants in and out of planters throughout the year.

Wooden empty rectangular pot for plant

What Are The Best Liner Materials To Use For A Planter Box?

Most liners are made of plastic. They come in various shapes and sizes, from transparent plastic sheets to plastic containers. In some circumstances, spray-on liners are also available.

Here are some of the best waterproof liner materials you can use:

Plastic Containers

This material is quite practical. You might put them in various containers, like your wooden planter. After watering your plant, you can return the entire container to the planter box.

If done well, your planter box won't ever come into contact with water, extending its lifespan.

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Plastic Sheeting

Plastic sheeting is a fantastic option if you want a more durable liner. Attach it to the interior of your planter box with staples or adhesive.

Just be sure to make holes for drainage in the plastic. Most plants will rot and die if left in water for too long.

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Resin

Planter boxes can be waterproof by lining them with a cloth dipped in resin. Your planter will be protected from moisture by a sealed layer that forms as the resin dries.

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Fiberglass

When you use this material, your planter will have a beautiful coating made of fiberglass that will shield it from moisture.

Unfortunately, dealing with fiberglass can be harmful if inhaled or handled, so be sure you have the proper safety gear.

Pond Liner

Another excellent choice for lining planters is pond liners. Although working with it can be pretty challenging. You must line the planter and make drainage holes to keep your plants healthy.

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Varnish

Another reliable defense for wooden planters is varnish. You only need to apply the necessary number of coats, and you're done.

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Spray-on Liner

Planter liners made of silicone or plastic that can be sprayed on are available. If you choose this course of action, you must first set up your planter before applying the necessary quantity of liner with a spray bottle.

When used to protect wooden boxes, this liner works incredibly well and helps the boxes endure considerably longer.

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What Are The Most Common Materials Used To Build Planter Boxes?

The industry offers a wide variety of planter materials. The appropriate material selection will significantly impact the health of your plants and add to the aesthetic value of your interior or outside.

The materials used in planters most frequently are:

Wood

Flower planter display at a home

Various kinds of natural materials are used to create wooden containers. The most prevalent types include rosewood, cedar, hemlock, fir, and pine. Bamboo pots, for example, are made of other materials that are pretty light.

These trees' lumber is harvested as planks and beams. To strengthen the pot's strength and waterproofing, this is next treated and cured for several months.

Pros

Cons

  • Made of natural materials and does not endanger the health of plants
  • Natural-looking as an outdoor planter and ornamental-looking when used indoors
  • Won't last much longer compared to other planter materials
  • The price of this material is costly 

Fiberglass

Wooden terrace on the lawn with fiberglass planter

Fiberglass is relatively new material. To generate it, glass is spun into a fiber and combined with resin to create an incredibly durable and flexible composite.

This mixture of fiberglass and resin is then poured into a mold to produce different shapes and sizes.

After a few rounds of sanding, the fiberglass planter is finished with a perfect and durable layer of primer. Drilling drainage holes into the bottom will allow appropriate drainage.

Pros

Cons

  • Very durable and adaptable
  • Useful both inside and outside
  • Incredibly lightweight
  • Incomparable in terms of their finish and strength
  • Plant-protection features (waterproofing, UV protection, prohibits chemical leeching)
  • Pricey
  • Some businesses use inferior materials while producing fiberglass

Concrete

Beautiful garden with blooming plants on concrete planter

Cement paste is mixed with water, sand, and gravel to produce concrete, which can be used to make a planter.

Pros

Cons

  • Due to their natural light-gray tone, concrete planters can be visually neutral in a crowded color scheme.
  • You can customize what color you want, should you decide to paint it.
  • Ideal for outdoor use since concrete is heavy and sturdy.
  • Customizable shape and size that will suit your taste. 
  • Not an environmentally-friendly material.
  • Lime from concrete might seep into the potting soil.
  • Concrete is fragile despite being sturdy.

Plastic

Plastic planter on the wooden box

Numerous types of plastic are available today for various uses, including uPVC, which is regarded as secure for use in food production.

Pros

Cons

  • Very inexpensive to produce and can be molded into any form or style
  • It has a very high strength-to-weight ratio
  • It has several adverse effects on the environment
  • It takes a long time to degrade
  • Organically hazardous compounds are released by plastic
  • When plastic is exposed to the sun and heat for an extended time, it can become highly brittle and shatter

Metal

Metal planter on the garden

Although many other types of metal containers are on the market, steel, aluminum, zinc, and copper are the most often used metals.

Pros

Cons

  • Metal containers are incredibly robust and long-lasting.
  • You can keep it outside to deteriorate without issues, and it won't chip, shatter, or scrape.
  • Any decor would benefit greatly from the inclusion of metal containers, especially given the variety of metals you can use.
  • Heavy and won't be knocked over that easily.
  • Heavy and hard to move around
  • Prone to rusting
  • It can get very hot when exposed to direct heat from the sun and can damage plant roots.

What Are The Benefits Of Lining A Planter Box?

Row of raised flower planters

Here are some benefits you can enjoy if you line your planter box:

  • The liner will enable you to remove the plant from the pot, allow the roots to drain correctly, and then replace it when you're planting in a pot or planter without drainage holes.
  • Liners protect the soil from extreme temperature fluctuations.
  • Pests such as gophers and moles can't damage your plants since liners will keep them away.
  • For newly constructed garden beds, bed liners are helpful because they separate the weeds from the seeds.
  • While keeping all of your healthy soil in the bed, lining the bottom with absorbent fabrics will allow water to drain into the ground.

In Closing

Using planter liners will help new or used garden planters, specifically wooden planters, survive longer.

Liners contain the planting media, preventing soil from getting on the planter box's external casing and regulating drainage. That's why it's also essential for you to know how to line your planter box.

Made it to the end? Check out these helpful related articles below!

13 Awesome Above-Ground Planter Boxes

How to Protect Wood in Raised Garden Beds and Flower Boxes