Let's Get to the Bottom of Raised Beds

Whether or not your raised bed will have a bottom depends on the type of raised bed, but I'd say most raised beds are bottomless. You don't really need a bottom unless your raised bed will sit on a surface you'd like to protect such as a wooden patio deck, a balcony, a porch, a concrete walkway, etc. Standing planters also, obviously, have bottoms so that they can hold the contents of the garden several feet above the ground.

Most of the raised bed kits you'll find for sale online will not have bottoms. The same goes for most directions for how to build your own raised beds.

Four-sided beds like the ones pictured above and below are meant to be set on gravel, grass, or mulch and then filled with good soil—that's the ideal drainage scenario. The last thing you want is for your raised bed to turn into a bathtub. Most herbs and veggies like a good soak, but they don't want their roots sitting in water too long.

So if your raised bed does have an enclosed bottom, make sure to check on the draining situation. You may have to drill drainage holes every 6 inches or so to allow water to pass through.

How Do You Prevent Soil from Washing Out of Your Raised Beds?

All you have to do to hold the soil inside your raised bed is put down some type of porous material. You can do weed barrier cloth or plain ol' burlap. For small containers and pots, you can even use coffee filters. Make sure to hold this layer in place as you fill your bed with soil. That way, your soil won't wash out the drain holes or the bottom of the bed every time you water or it rains.

Some gardeners get upset when they hear me recommend putting weed barrier cloth at the bottom of a raised bed. They grow in low raised beds and allow the roots of their plants to push into their native soil. I recommend growing in raised beds that can accommodate the entire root system of your plants for several reasons. You can learn more about the best raised bed height based on the type of plants you want to grow here.

But How Do You Keep Out Weeds?

The height of a raised bed can keep most weeds from popping up, but there are measures you can take to ensure weeds don't rear their ugly, unwanted heads. Add a physical barrier like burlap or weed barrier cloth to the bottom of your bed before you shovel in the soil. You could even use several layers of cardboard as a weed barrier. Just make sure to remove tape and any areas with glossy print first. The cardboard will break down in about 4 to 6 months.

What If I Need My Raised Bed to Have a Bottom to Keep Out Pests?

If you live somewhere with pests that like to burrow into gardens to eat your plants (think voles and moles), then the easiest way to keep them out is to actually put hardware cloth at the bottom of your raised bed. You'll need to do this before you fill your beds with soil. You can layer landscape fabric or cardboard on top of the hardware cloth for weed control. You'll get to enjoy the protection these barriers provide, but you won't have to sacrifice good drainage.

Raised Beds with Bottoms

You might notice that most of the raised beds with bottoms are made of steel. That's because steel (galvanized steel, Corten steel, and powder-coated steel are great options) is a strong enough material to support the weight of the entire raised bed once it's filled with soil.

Here are some steel raised bed options:

• Our Corten Steel Raised Bed Container has a metal bottom panel. I actually tried to build one without this panel for my own garden, but the bed can't be put together without it. This container is great for growing on patios, porches, and decks thanks to this bottom panel. There are several large drainage holes in the bottom.
• Our Corten Steel Raised Garden Bed on Wheels is another great option for patios and porches. The casters have brakes, so you can roll this bed around your space and then lock it in place. The beds come with drainage holes.
• Our Aluminum Raised Bed on Wheels is strong but super lightweight, perfect for decks with weight limitations. I have two of these on the back deck of our home. The bottom of the containers are powder coated for greater durability and have drainage holes.
• DIY option: You can make your own rolling steel planter by grabbing a large steel trough and adding casters (and drainage holes, of course). Here's how to make your own rolling steel planter.

Steel is far more durable than wood, so these beds are going to last decades, even in humid or rainy climates.

Wood Raised Bed Options

Wood raised beds only have bottoms if the beds themselves are lifted off the ground. We have two standing planters in the Gardenary Shop: one with caps on the corners and one with just top trim. Instead of having drainage holes, small gaps between the bottom slats allow water to drain from the planters. These elevated planters are the perfect height to make planting and harvesting as convenient as possible.

Since wood is not as durable (even rot-resistant woods like cedar), I recommend staining the inside of your planter with something like our Eco Restore Wood Treatment to enjoy greater longevity with your raised bed. Before adding soil, make sure to spread a piece of landscaping fabric over the bottom slats to keep soil inside the bed when watering.

We're Here to Answer All Your Raised Bed Questions

Gardenary is the place to come for answers to all your raised beds questions.

Whether your raised bed has a bottom or not, make sure to fill it up with great, nutrient-rich soil. Your plants will thank you!