Can Worms Move Through Pea Gravel Raised Garden Bed

Raised gardens are becoming increasingly popular due to their many benefits. They serve as a barrier to pests, prevent soil compaction, and have better drainage than traditional gardening.

I must point out that I've recently built two raised garden beds and have done extensive research on what to put at the bottom of them.

But what do we put at the bottom of a raised garden bed? Do we have to put anything at all?

With that being said, each person is different, and a particular material may work better for you. So, make sure you consider each option carefully.

What to put at the bottom of a raised garden bed? The bottom of your raised garden bed can be lined with many different options. The most popular options are landscape fabric, newspaper, cardboard, plastic, and concrete. Each option has its pros and cons and will depend on your situation. However, a raised garden bed should never be placed on the ground without anything underneath.

What to Put at The Bottom of a Raised Bed?

Landscaping fabric

Landscaping fabric is a popular option, and for a good reason. Let's go over some pros of landscaping fabric:

long-lasting
discourages weeds
allows moisture to pass through it
environmentally friendly

Landscaping fabric will last you many seasons. I have even met people saying it lasted 7-10 years before needing a replacement. However, plant roots can grow through the fabric, which lessens the effectiveness every season. Also, each time you dig a hole, the material can be damaged.

Another drawback with landscaping fabric is that it prevents earthworms from passing through into the soil.

Earthworms are some of the hardest working creatures in the garden, and without them, your garden soil won't be the best it can be. Worms process organic material and recycle the contents back into the soil. They also create tunnels underneath the soil for water, air, and roots. As a result, the soil structure is improved.

In my opinion, the cons outweigh the pros. This is a deal-breaker.

Cardboard

Using a layer of cardboard underneath your raised garden bed can be a great way to suppress weeds. It lasts slightly longer than the newspaper, generally about 3-6 months. It also provides humus to the soil as it breaks down. Additionally, cardboard allows good microbes and worms to enter the raised bed as it breaks down. This option is my personal favorite and has given me great success in the past.

Newspaper

The newspaper method is similar to cardboard, but it doesn't last as long. It suppresses weeds well, but you will need a few layers. Additionally, using newspaper allows microbes and worms to enter the raised bed. It also provides humus to the soil as it breaks down. I like the newspaper option, but I prefer cardboard over it. I've had weeds grow up through layered newspapers, but I've never had that happen with cardboard.

One con of using newspaper as a bottom is that it tends to blow around pretty often. So you will need to wet it down and place something on top of it to prevent that from happening.

Sheets of Plastic

Plastic is definitely good at suppressing weeds, but it doesn't provide excellent drainage. For this reason, you must drill holes in the plastic to provide drainage. This will allow water to pass through the plastic and prevent your plants from becoming waterlogged. Plastic is similar to landscaping fabric in the fact that it can last years without needing to be replaced. However, it's worse than landscaping fabric at allowing earthworms into the soil.

Concrete

There are some situations where concrete for a bottom may be a good option. If your soil has inferior drainage or is mostly clay, concrete can be a good alternative. It's obviously great at suppressing weeds, but I think it's overkill for the majority of people.

Also, concrete cannot retain water, and deep-rooted plants won't be able to grow effectively unless the raised bed is at least 12 inches deep. You will also need to think about how the water is going to drain out the bottom.

Overall, placing a raised garden bed on concrete can provide a unique look to any area.

Why You Should Always Put a Bottom on Your Raised Garden Bed?

If you put your raised garden bed directly on grass and weeds without anything at the bottom, this could lead to many issues for you. For example, this could lead to grass and weeds growing up through the soil and into your raised garden bed.

One of the main benefits of using a raised garden bed is that it reduces the need to pull weeds. However, if you don't take the necessary steps in order to ensure weeds are smothered out, you will have to weed often. This is why having a bottom on your raised garden bed is essential.

What to Do Before Placing Anything Underneath Your Raised Bed?

Before we get ahead of ourselves, it's vital to lay a good foundation for the bottom of our raised bed. We can do so by solarizing the grass, mowing as low as possible, or digging the top layer of grass. Whatever option you choose, you can ensure that your raised garden bed will have an excellent foundation.

Let's quickly go over what each choice consists of.

If you don't want to dig up the grass, there are other options. For example, you can solarize the grass weeks beforehand; this will ensure all perennial weeds are dead, which will make it much easier to work the ground. Or you can mow the grass as low as possible if you're looking for something quick and easy.

Although you don't have to dig up the grass and level your raised garden bed, it does tend to look nicer. However, as long as you place your raised garden bed in a semi-level area, you shouldn't have any issues placing it directly on the grass.

How to Get Free Material for the Bottom of Your Raised Bed

Whatever option you decide to use, it doesn't have to be complicated. In fact, you can find the first two options for free many times. If you need some cardboard to line the bottom of your raised garden bed, you can go to any store and ask when they get their truck deliveries. If you ask them to save the boxes, you can get them after they are done unloading the delivery truck. In the past, I have gained enough free cardboard for ten raised beds.

On the other hand, if you're interested in using the newspaper method, start collecting your newspaper from your weekly route and ask neighbors for any extra they have.

Should I Put Rocks in the Bottom of My Raised Garden Bed?

Although raised garden beds are known for having excellent drainage, some people use rocks such as pea gravel to further increase drainage. That being said, pea gravel is an excellent choice to improve drainage, specifically for raised garden beds that are 12 to 18 inches tall or in poor drainage areas.

However, I wouldn't recommend using rocks in a small raised garden bed that doesn't have a lot of depth. I say that because many vegetables you'll be growing will have a deep rooting system that could be halted if rocks are in the way.

Conclusion

When you decide you want to build a raised garden bed, it's easy to become overwhelmed with all you must do to get it ready. But by looking through each option, you can make the decision process much easier and find an option that will work for lining your raised garden bed.