Most people want to know if they should put anything on the bottom of their raised garden bed. The benefits of a raised garden bed are plentiful. For one, you save your energy and can reduce back pain.
However, the question today is what to put on the bottom of your raised garden bed. Typically, you want a layer of organic material. This can include wood chips, leaves, straw, or grass clippings.
You may also want to consider cardboard on top of that. The organic material is turned to compost, and the cardboard prevents weeds from popping up.
It’s essential for you to understand why the process is necessary. That way, you can be a better gardener and give your plants what they need.
Table of Contents
- Why Use Newspaper or Cardboard
- Other Barriers Instead of Newspaper and Cardboard
- The Soil You Need for a Raised Garden Bed
- The One Rule to Follow for Your Raised Garden Beds
- Do You Need a Bottom for the Raised Garden Bed?
- Caution for Treated Wood
- What About Green Manure Cover Crops?
- Top off Your Soil
Why Use Newspaper or Cardboard
You should consider using newspaper or cardboard at the bottom of the raised garden bed. This is going to keep out the weeds.
We recommend that you put a single cardboard layer in the bottom. Alternatively, you can get five or six layers of some newspaper for the bottom of the bed.
Make sure that you’ve covered the entire base. That way, no weeds can find a space to creep in from outside. We recommend that you use a heavy mulch layer on top of the cardboard or newspaper.
There is a good reason for using newspaper or cardboard for the raised garden bed. Ultimately, the paper acts as cellulose and is organic. That means the soil is going to be even more fertile, which makes it easier to work with.
If you use newspaper or cardboard in the bottom of a raised garden bed, it is going to break down. However, it’s going to last long enough to prevent the weeds from gaining a foothold.
Most people have an issue with retaining moisture in their raised garden beds. You can easily solve this issue by using straw mulch. It’s going to keep the soil moister, and it helps to keep out the weeds, too.
You’re going to need about 3 to 4 inches of mulch or straw. In the spring, you can just spade it in or use a small shovel. Still, you’ve got to be careful that you don’t go too deep into the soil. Otherwise, you risk bringing weed seeds from underneath, making it easy for them to sprout.
Other Barriers Instead of Newspaper and Cardboard
Some gardeners believe that you can add carpet or another blanketing barrier to the bottom of the raised garden bed. This is designed to protect the roots of the plants. However, this is not a good idea!
If you put carpet on the bottom of the bed, it is going to slow the drainage down. Plus, some vegetables may have limited root growth from the carpet.
The same is true if you use other barriers, such as plastic bags. Instead, you should stick with newspaper and cardboard because they’re biodegradable.
The Soil You Need for a Raised Garden Bed
Many gardeners like to buy their soil in bulk, such as by cubic yard or cubic foot. This is extremely helpful if you’re filling multiple raised beds. It can be hard to figure out how much soil you need, and you don’t want to run out.
Typically, you want these soil proportions:
- 60% topsoil
- 30% compost
- 10% potting soil
It’s best to choose a soil-less growing mixture for your potting soil. For optimal results, choose one with vermiculite, peat moss, and perlite.
These are just approximate percentages. The soil volume could vary between the soil manufacturers. On top of that, you should always round up because you never know what might come into play.
Some areas might not have top-quality topsoil. If that’s the case for you, consider using a blend of soil-less medium and compost with a 50/50 blend. It’s usually called potting soil, and it can be just as good as topsoil.
You can choose to add peat moss to the raised bed. However, when you’re mixing everything together, make sure there’s only 20 percent peat moss.
Most people don’t know that peat moss is naturally acidic. Therefore, it might not be ideal for vegetable beds. Still, a little isn’t going to hurt.
The One Rule to Follow for Your Raised Garden Beds
A raised garden bed is gorgeous because it has rich, full soil. It looks dark and amazing. However, this means that you should never step onto the soil.
Well-drained, light and fluffy soil must be developed over time. You spend a lot of work getting it just right, and this is the main advantage of a raised garden bed. Ultimately, such great soil ensures that you have vibrant plants and more growth.
However, if you end up stepping on the soil, it’s going to get compacted. That reduces aeration. Ultimately, that means that microorganisms don’t grow and flourish, which means your plants don’t get all the nutrients they need.
Do You Need a Bottom for the Raised Garden Bed?
You aren’t required to have a bottom if the raised garden bed sits directly on the ground. In fact, you only need a bottom if you want to protect the surface. This can include wooden decks or flat roofs.
While you don’t have to put a hard bottom on the raised bed, many gardeners like to. At the very least, you should use weed fabric. That way, weed seeds can’t germinate in the soil and kill your plants.
Weed fabric works similarly to cardboard. It blocks the weeds and helps with drainage.
Caution for Treated Wood
You should be thinking about what to put in the bottom of your raised garden bed. However, it’s also essential to be cautious about the materials you use to build it.
Treated lumber often contains toxic chemicals. They’re designed to keep the wood safe from rot and termites. However, those chemicals can easily get into the soil.
Ultimately, the plants could absorb the chemicals, and that’s not good for them. On top of that, you may be growing food, and that can lead to you and others getting sick.
Typically, treated wood isn’t as bad for flowers. Still, some plants could die or look sickly if they absorb any of the chemicals.
What About Green Manure Cover Crops?
Green manure cover crops are usually planted between the crop rotations. It’s also possible to plant them in winter.
The goal here is to add more organic material to the soil. That way, it creates its own fertilizer and feeds the plants next season.
You have to turn under the green manure cover crops before the seed. In most cases, you have to do it many weeks before replanting your raised garden bed.
Top off Your Soil
The soil is going to constantly settle in a raised garden bed. Therefore, you may notice that the level is much lower in spring than it was in the fall.
Try digging up a little soil and look at it. Is it compacted or still crumbly, light, and moist? If it’s unmalleable, you should add peat so that it fluffs back up.
It’s important to know what to put on the bottom of a raised garden bed. Now that you understand what to do, you are sure to have a beautiful garden. Ensure that you’re using appropriate soil, compost, and cardboard/ newspaper to reap the bounty later.