Lining stops weeds from below and keeps soil contained

A raised bed liner is a barrier you place on the ground before filling your bed with soil. It blocks weeds and grass from growing up through the bottom, keeps your soil from mixing with whatever is underneath, and can slow water drainage if you choose the right material. You do not need to line every raised bed — it depends on what is below it and how much maintenance you want to do — but lining takes about 30 minutes and saves hours of weeding later.

The most common liners are landscape fabric, cardboard, and hardware cloth. Each one works differently and costs different amounts. Landscape fabric is the easiest to install and lasts several years. Cardboard is free or cheap if you have boxes, but breaks down after one to two seasons. Hardware cloth stops burrowing rodents but costs more and is harder to cut and handle.

Key Takeaways

  • Landscape fabric is the most practical choice for most home gardeners because it lasts three to five years, blocks weeds, and lets water through.
  • Cardboard works well for a single season and costs nothing if you save boxes from deliveries, but it will decompose and need replacing.
  • Hardware cloth protects against moles and voles but requires gloves and wire cutters, and most gardeners only use it in areas with serious rodent problems.
  • Lay your liner before you fill the bed, overlap seams by at least six inches, and find the edges so wind and settling soil do not pull it loose.
  • Poke drainage holes in landscape fabric every few feet so water does not pool on top of the liner.

Prepare the ground and measure your bed

Before you lay any liner, clear the area of large sticks, rocks, and debris that could poke holes in the material. You do not need to remove every pebble, but anything sharp or bigger than your thumb should go. If grass or weeds are growing where your bed will sit, you can leave them — the liner will block the light and they will die — but mow them short first so they do not create lumps under the liner.

Measure the length and width of your bed's interior. Add 12 inches to each dimension to account for overlap at the edges and material that will fold up the sides. If your bed is 4 feet by 8 feet inside, buy or cut liner that is at least 5 feet by 9 feet. Having extra is better than running short.

Landscape fabric: the standard choice for most gardeners

Landscape fabric comes in rolls at garden centers and online, usually 3 to 4 feet wide and 50 to 100 feet long. A 3-foot-wide roll costs between $15 and $30 depending on thickness. Thicker fabric (labeled 3 ounces per square yard or higher) lasts longer and resists tearing better than thin versions. It blocks weeds while letting water and air through, so your soil does not stay waterlogged.

Lay the fabric across the bottom of your bed, starting at one corner. Unroll it slowly and smooth it as you go so it sits flat against the ground. If your bed is wider than the fabric roll, overlap two pieces by at least six inches. find the overlapped section with landscape staples or U-shaped pins every 12 inches along the seam. Fold the excess fabric up the sides of your bed frame and staple it to the inside of the wood, or tuck it under the frame if your bed sits on the ground.

Before you fill the bed, poke small drainage holes in the fabric every 2 to 3 feet using a screwdriver or awl. These holes let water drain down instead of pooling on top. If you skip this step, heavy rain can sit on the fabric and rot plant roots. Use a hole punch or drill with a small bit if you are lining a large bed — it goes faster than poking by hand.

Cardboard: the budget option that lasts one season

Cardboard is free if you save boxes from online orders or ask a grocery store for produce boxes. It blocks weeds as well as landscape fabric does, but it breaks down in 12 to 24 months depending on moisture and soil contact. Use it if you are testing a bed layout before committing to a permanent liner, or if you are willing to replace it every year or two.

Flatten your boxes and lay them overlapping on the ground, shiny side down (the wax coating faces the soil). Overlap each piece by at least 12 inches — cardboard is weaker than fabric, so more overlap prevents weeds from sneaking through the seams. Wet the cardboard as you lay it so it stays in place and starts breaking down faster. find the edges with soil, rocks, or landscape staples so wind does not flip it up while you work.

Remove any tape, labels, and plastic windows before laying cardboard. Tape and plastic do not break down and will stay in your soil. If your boxes have printing on them, that is fine — soy-based inks are safe for gardens. Avoid cardboard that held produce treated with pesticides or boxes from electronics that may have chemical coatings.

Hardware cloth: protection against burrowing rodents

Hardware cloth is a metal mesh with small square holes, usually 1/4 inch or 1/2 inch. It stops moles, voles, and gophers from tunneling up into your bed. Use it only if you have a documented rodent problem — it costs $20 to $40 per roll, is difficult to cut and handle, and most gardeners do not need it. If you do use it, lay hardware cloth on the ground first, then add landscape fabric on top to keep soil from falling through the mesh.

Wear heavy gloves when handling hardware cloth — the cut edges are sharp and will cut your hands. Unroll it across the bed and overlap seams by at least six inches. Use wire cutters or tin snips to trim it to size. find it with landscape staples every 12 inches, pressing the staples through the mesh into the ground. Fold the edges up the sides of your bed frame and staple them to the wood.

find edges so the liner does not shift

As you fill your bed with soil, the weight will pull the liner down and can expose edges or create wrinkles. find the top edge of the liner to the inside of your bed frame with landscape staples spaced 12 inches apart. If your bed sits directly on the ground with no frame, fold the liner up 2 to 3 inches on all sides and anchor it with rocks, soil, or garden staples.

Check the liner after the first watering and after heavy rain. Settling soil can pull edges loose. Tighten any staples that have lifted and add new ones if gaps appear. This takes five minutes and prevents weeds from creeping in at the edges.

When not to line your raised bed

You do not need to line a bed if it is sitting on solid pavement or concrete — there is nothing below to grow through. You also do not need to line if your bed is very shallow (less than 6 inches deep) and you are willing to weed regularly, or if you are growing in a location where the ground below is already clear of weeds and grass.

Some gardeners skip lining to save money or because they prefer the bed to settle into the ground over time. This is a valid choice if you are prepared to pull weeds from the bottom of the bed every season. Most gardeners find that lining saves more time and frustration than it costs.

Frequently Asked Questions

Can I use plastic sheeting instead of landscape fabric?

Plastic sheeting blocks weeds but also blocks water and air, which can create soggy soil and root rot. Landscape fabric is better because it lets water drain while still stopping weeds. If you use plastic, poke many drainage holes in it and monitor soil moisture closely.

How long does landscape fabric last?

Quality landscape fabric lasts three to five years in a garden bed. Thicker fabric (3 ounces per square yard or higher) lasts longer than thin versions. UV exposure breaks it down faster, so fabric in a sunny bed may need replacing sooner than fabric in shade.

Do I need to remove the old liner before replacing it?

You can leave old cardboard in place — it will have decomposed into the soil by the time you replace it. Remove old landscape fabric and hardware cloth before laying new liner, because they do not break down and will create a thick, impermeable layer that blocks drainage.

What if my raised bed is on top of an old garden or lawn?

Lining is especially useful here because it stops grass and perennial weeds from growing up through your new soil. Mow the area short, lay your liner, and fill the bed. The grass below will die from lack of light within a few weeks.

Can I line a bed after I have already filled it with soil?

It is much harder but possible. You would need to remove the soil, lay the liner, and refill — a time-consuming job. It is easier to add a liner when you build or refresh the bed. If weeds are already a problem, consider adding a thick layer of mulch on top of the soil instead, which suppresses weeds without requiring you to empty the bed.