Gardening on raised beds has immense advantages over planting directly in the soil.
It prevents weed growth and stops rodents from destroying your crops.
It also allows better drainage and keeps the soil warm in winter for a longer cultivation season.
But the question is, what to put on the bottom of a raised garden bed to get all these benefits?
What to Put on Bottom of Raised Garden Bed
The best materials include cardboard sheets, dried plant roots, a layer of cardboard, grass clippings, wood chips, and a layer of newspaper.
You can use all these materials in various ways, which we’ll explain in detail.
If you’re looking for an effective and cheap solution for your raised bed garden, cardboard is an excellent choice.
You can easily get it from your local grocery store without charge, so it’s a highly economical option.
You can even pair it with straw to add another layer.
The cardboard stops the growth of weeds underneath and decomposes slowly by adding organic matter.
It also traps optimum moisture in the soil but is breathable not to choke the plant roots.
To use, make sure you remove all the tape, stapler pins, and plastics from the cardboard before you spread it under your raised bed bottom.
You can also choose dry leaves if you want to keep the whole raised bed organic.
Not only will they protect against weeds and termites, but the decomposition of leaves will act as organic fertilizer and increase soil fertility.
When using leaves, don’t just spread them in a single layer but make a thick two to four inches bed of leaves.
You can also use layers of newspaper or cardboard before using leaves.
Adding small to medium size gravel before making the bed with leaves is also a good option, as it helps to stop drainage.
However, it’s better not to use eucalyptus tree leaves as they can hamper plant growth.
Organic materials are the best when it comes to making raised beds. Straw is a highly effective material in protecting plants from rodents, weeds, and termites.
It’s also beneficial in keeping enough moisture in the soil and creates humus that improves plant growth.
A layer of newspaper or cardboard goes well with straw too.
Like tree leaves, straw also decomposes and shrinks, so you’ll need to add more soil to keep your bed level intact.
The decomposition is not a disadvantage, as it adds organic matter to the soil.
Using rocks and stones as a raised bed garden is beneficial but also tricky. The use of rocks may increase or decrease drainage depending on the placement of the layer of rocks.
If you use too many rocks and make the layer too thick, the water will not drain properly, causing saturation and waterlogging in the soil.
However, when you put heavy clay soil as the upper layer, rocks help filter water slowly but steadily and prevent saturation.
It’s also a long-term solution since the rocks will not decompose, unlike organic matter.
Wood is an optimum choice if you are looking for decomposing organic material that can last a long time.
A layer of wood chips will not only stop weeds from growing but also create a breathing environment for your plants.
Wood chips are also great for beneficial bacteria and do not harm the soil. If there’s little nitrogen in your garden soil, avoid using wood chips, as they can make the soil acidic.
You can also use tree branches, twigs, and logs, but they will not stop the growth of weeds as they do not form a compact layer.
Most carpets are made of plastic or fiber, harming your soil and limiting plant growth.
However, carpets made of organic materials are excellent choices for raised bottom beds.
These carpets are made of cotton, jute, hemp, or other organic materials.
They’re beneficial since they decompose slowly and choke the weeds underneath.
At the same time, it will allow oxygen and water to pass through, preventing saturation.
A bed garden with landscape fabric will not decompose easily and may last for more than a decade without needing replacement. It’s not a free option, but it is a durable one.
The best thing is that it allows water to pass through, preventing saturation in the soil by improving drainage.
Note that landscape fiber is not the same as landscape plastic. Both are great at choking the weeds, but landscape plastic does not allow any water through it, trapping it in the bed.
The result is a drainage and water logging threat.
The only issues with landscape fiber are that it’s not free, and you have to replace it after ten to twelve years.
Hardware fabric or cloth is a fine mesh made of iron or other metals. It does not stop weeds or termites but is highly effective against rodents.
It does cost money, but it is necessary where you know rodents or other small animals will attack from below the garden bed.
The drawback of hardware fabric is that you cannot use it alone. You have to add other materials, such as grass clippings or wood chips, to keep the weeds out.
The fabric also erodes over time, so you must replace it after ten years, but it’s definitely worth the money.
What to put on bottom of raised garden bed to prevent water logging, weeds, termites, and saturation?
The best options include wood chips, a rocks layer at the bottom with an upper layer of clay, cardboard chips, newspapers, and dry leaves.
To stop rodents, you can use a landscape fabric at the bottom of any bottom layer material you choose.