As we all know, gardening on a raised garden bed is a good choice to prevent weeds. It also makes it easier to control improved soil, better drainage and less back work. But what should I put at the bottom of the elevated garden bed?

raised garden bed

The most commonly used materials for the bottom of raised garden bed are cardboard, covering, concrete, fabric and plastic. They act as a barrier between the garden soil and the ground to prevent weeds from passing through and to prevent toxins and other pests underground.

1. Cardboard

Cardboard is everywhere. If your budget is limited, this is your best choice. It's also easy to put cardboard under an raised bed.

Just lay the boards on the bottom and fill the soil, and you're done!

However, the cardboard will decompose within 4-6 months. Therefore, it is best to use several pieces of cardboard to form a thick layer under the raised garden bed for the best effect.

Just make sure not to use glossy cardboard, as it may release harmful plant toxins.

2. Hardware fabric

If you build an raiseed garden on concrete, the hardware fabric is most suitable as the underlay of the raised garden bed.

Choose galvanized hardware fabric to avoid sagging and rusting over time. Lay landscape fabrics on it to make a sturdy and durable garden bed.

How to place the metal fabric basket under the elevated bed:

  • Get the inside dimensions of the garden bed. Add a few inches of extra slack and cut it with metal shears.
  • By imitating the shape of the bed to form a basket, the extra slack is bent upwards. Try to make both sides as even as possible.
  • Push the basket to the bottom. You may need to step on the wires inside the bed to install them properly.
  • Secure it in place with wide head screws.
  • You can add a layer of landscape fabric to fix the soil. Then, add soil and place the plants there.

The use of hard wire fabric on the raised garden bed with a bottom can provide good drainage effect, while protecting your plants from pests, such as hamsters, which can eat all your crops.

raised garden bed

3. Plastic

A variant of the raised garden bed is with legs. If you have back problems, it is easier to reach and most beneficial. It is ideal to use lightweight plastic as the lining of an raised garden bed with legs.

How to use plastic as garden bed lining:

  • Buy an old pool cover or plastic tarpaulin. If not, you can use the shop's polypropylene garden bed liner.
  • Measure the bottom of the raised bed and cut the plastic according to it.
  • Before laying the plastic under the raised bed, cut a drain hole on the plastic to let the water drain.

Using the plastic lining as the base of the raised garden bed can protect your plants from toxins that may be present in the raised garden bed frame.

In addition, if your soil is too dry and you need to keep it moist, it is the best material.

Otherwise, there are other options, including permeable materials and plastics made of polypropylene fabric, which can better drain water.

4. Mulch

Covering the bottom of the raised bed is another good choice.

  • It can be organic, consisting of chopped parts of plants and compost and other materials.
  • Or you can use inorganic mulch, including rock, gravel, plastic, or rubber.

Both types of mulch prevent weeds from growing and retain water for plants. However, in the long run, organic mulch contains nutrients that are beneficial to plants.

For example, covering the bottom of the raised bed with straw can effectively prevent weeds from entering and maintain moisture.

How to add a cover to your raised bed:

  • Prepare enough mulch to cover the bottom of your raised bed and remove weeds from the soil you will add to the garden bed.
  • Use a shovel or your hands to place a 2 – 4 inch covering. Do not place more than required, because too much mulch may suffocate plants. Also, make sure they are placed approximately 3 inches from the base of the plant.

After the mulch is evenly spread, you can add a layer of soil to the pot.

raised garden bed


Raised garden beds have many advantages. It allows you to better control the soil, protect your plants from underground weeds and other pests, and requires less maintenance. Many materials can be used for raised garden beds, including cardboard, coverings, hardware fabrics, and plastics.

So, what should I put at the bottom of the raised garden bed? This may depend on your budget, the availability of materials near you, and their advantages and disadvantages. We hope we can help you make a choice based on the information in our posts.

December 11, 2022

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