How to Prepare the Ground for Raised Beds in 7 Steps
Hold it right there! Before you place your new raised bed in your garden and start growing, you should complete a few other steps. Briana Yablonski shares seven steps for preparing your ground for raised beds.
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Maybe you’ve just bought a brand-new raised bed and can’t wait to start planting. Or perhaps you’ve moved to a new property and are thinking about how to lay out your garden beds. No matter the case, establishing a raised bed isn’t always as simple as placing it on the ground and filling it with the proper material.
Like with most things in the garden, a little bit of extra work up front helps you save time and frustration in the future. Preparing your ground before setting up your beds helps limit weeds, prevent erosion, and keep everything neat and tidy.
I’m going to share seven steps that will help make your ground ready for your garden beds. While you may not have to complete all of these steps, read through the entire list and see which ones apply to your situation.
Determine the Number and Size You Need
You can find raised beds in just about every length, width, and height, so think about which size works well for you and your garden. While you may be tempted to go with one large bed rather than a few smaller beds, remember that you’ll need to be able to reach all parts of your beds to plant, weed, water, and harvest your crops. Most people find a bed should be no wider than four feet to make sure you reach both sides of the bed. If you’re placing one side of your bed against a wall or other structure, keep it under three feet wide.
Along with determining the size, think about the number you’d like to install. If you plan on adding more in a year or two, consider what size they’ll be and where they’ll go.
Lay Out Your Beds and Pathways
The first step in preparing the ground is establishing a proper layout. Taking time to measure the areas of your beds and pathways will save you headaches during the installation process and ensure you have plenty of space to maneuver around your beds.
Consider the following factors when planning where to place your raised bed.
Sunlight
Most vegetables, herbs, and cut flowers grow best in full sun, so position your raised beds in a location that receives at least eight hours of direct light each day. It’s okay if the area receives a few hours of sun in the morning or evening, but avoid locations with full shade.
Pathway Width
If you’re placing multiple raised beds next to each other, think about the ideal pathway width. While you may want to keep the pathways small to save space, think about how much space you’ll need to comfortably walk and crouch between the beds.
You should also make sure the paths are wide enough to accommodate tools like wheelbarrows and harvest carts. While there isn’t one perfect pathway width, many gardeners find a two-foot or three-foot path works well.
Obstacles
There’s nothing wrong with placing a raised bed next to a wall or fence, but make sure these structures won’t prevent you from accessing your garden bed. If you plan on placing the bed next to an obstacle, consider a narrower bed.
Drainage
While you can alter soil drainage to some degree, it’s difficult to transform a soggy area of your yard. Placing a raised bed in a low-lying and poorly draining area can lead wood beds to decay more rapidly. Plus, it’s no fun standing and working in swampy ground.
Water Source
An easily accessible water source makes watering your plants a breeze. Whether you plan to install a drip irrigation system or water your plants with a hose, make sure a spigot is within reach of your beds. If your beds are far away from a water source, you’ll have to haul water in a bucket or watering can, which is both tiring and tedious.
Once you have a good idea of where to place your raised bed, use stakes and string to visually lay out your beds. While this step is optional, it allows you to see if you’ll be happy with the bed layout and pathway width.
Survey the Native Soil and Vegetation
After you’ve determined the size and location for your new garden, look at the environment you’re working with. Gardeners often think their native soil isn’t important, since they’ll be filling the beds with soil optimal for plant growth. However, paying attention to the preexistent soil and vegetation is still important.
If you’re using a tall raised bed, plant roots are unlikely to reach the native soil. Therefore, the soil texture and nutrient composition aren’t too important. However, if you’re installing a shorter style, many plant roots will eventually make their way to the native ground. That means you should ensure the soil isn’t extremely compacted or poorly draining.
If you’re dealing with compacted or waterlogged soil, take steps to improve it before placing your beds. A digging fork, shovel, or broadfork can help you aerate compacted soil, which will also improve drainage.
You should also examine the vegetation in the area. Annual plants like henbit and chickweed are easier to control than perennial grasses and weeds, so you won’t have to put too much work into removing them. Similarly, lawns made from grasses without stolons and rhizomes can be easily controlled by a low mow and light tarping.
However, if you’re dealing with invasive plants like Bermudagrass, thistle, and vinca, you should thoroughly remove them before building your raised bed. I’ll cover removal methods in more detail below.
Remove Perennial Weeds
If you’re dealing with perennial weeds like bindweed, bermudagrass, and thistle, you should remove them before installation. While six inches of soil is often enough to kill annual weeds like chickweed, carpetweed, and lambs quarter, many perennial weeds will continue to grow through any soil you put on top of them.
Therefore, the best option is to kill the weeds in the early stages. I recommend removing the weeds under your beds and pathways as well as those in the surrounding few feet.
There are multiple ways to kill these perennial weeds. The best option for you depends on the amount of time between now and when you want to add your garden, your available tools, and the time and effort you’re willing and able to commit to the project. Here are a few different ways you can remove perennial weeds.
Smother the Weeds
If you’re not in a rush to get your planters on the ground, smothering weeds is a great option. It’s a passive method, so it’s easy on your body and doesn’t require much hands-on time. There are two main ways you can smother weeds: occultation and solarization. Occultation involves using an opaque material to cut off light until weeds and their roots die. Solarization involves using a clear tarp to trap heat and cook the plants under the tarp.
Depending on the time of year, the material you use, and the present weeds, it can take anywhere from one to six months to completely kill the weeds. Regardless of which material you use, you should lay the material flat on the ground and weigh it down well.
Silage Tarp
If you’re serious about gardening, a silage tarp is the best tarp to have in your toolbox. These tarps are UV resistant, so they won’t break down when exposed to the sun. They cost more than standard black tarps used as moisture barriers, but they hold up much longer. Plus, you won’t have to worry about them breaking down into hundreds of tiny pieces of plastic.
Many silage tarps are white on one side and black on the other. Laying the tarp with the black side up heats the ground which speeds up weed seed germination and the death of perennial weeds. If you lay your silage tarp on the ground during the summer, most weeds will die within a month.
Cardboard
If you don’t want to shell out money for a silage tarp, you can use pieces of cardboard to smother weeds. As the cardboard breaks down, it adds organic matter to the soil, releasing nutrients and feeding microbes.
However, cardboard often breaks down before rhizomatous weeds like bindweed and bermudagrass are dead. Therefore, cardboard is most useful if you’re dealing with easy to kill perennial weeds like crabgrass and dandelions.
Remove the Weeds by Hand
If you want to install your new beds in your garden next week, adding a tarp or piece of cardboard won’t have much impact on aggressive perennial weeds. A quicker but more physically intensive method is removing the weeds by hand. If you use this method, treat the ground as you would if you were about to plant seeds or transplants.
You can use a hoe to remove annual weeds and perennial weeds with shallow root systems, but you’ll need to use more intensive methods on weeds with taproots and rhizomes. I recommend using a digging fork to loosen the soil and, therefore, the weeds’ roots.
You can then remove the rhizomes and roots by hand or with the help of a digging tool. Try to avoid chopping rhizomes of weeds like Bermuda grass and Johnson grass since this will just lead to more weeds.
Level the Ground
Placing a raised bed on sloped ground is difficult, so leveling the ground before setting your bed makes the process easier. The best tools for the job depend on the type of slope you’re dealing with. If one side of the ground is only a couple of inches taller than the other, you can use a rake to level the ground. However, if the ground below the bottom is six or eight inches higher than the ground below the top of the bed, you’ll need to grab a shovel to complete the job.
The ground doesn’t have to be completely level, but aim for a surface that is as level as possible. Not only will a level surface make it easy to place and fill the beds, but it will also allow water to infiltrate the top of the soil instead of running across the bed.
Make a Plan for Pathway Maintenance
Many gardeners make the mistake of forgetting about their pathways. I admit that it’s easy to focus on the veggies and flowers you’ll grow in your raised beds, but unattended pathways can quickly lead to weeds, erosion, and other problems. Trust me, I’ve been there!
You can choose many different materials for your pathways, and one option isn’t necessarily better than the other. Thinking about material cost, maintenance time, and appearance can help you choose an option that works for you.
Here are some popular options for raised bed pathways as well as pros and cons.
Living Pathways
Don’t want to remove that lush, green grass you have growing between your raised beds? You don’t have to! Living pathways consist of any type of plant, but popular options include white clover and ryegrass.
By keeping plants growing in the pathways, you limit erosion, improve water infiltration, and also keep your garden looking lush. However, you’ll have to mow your pathways at least a few times a season. And if you’re not careful, weeds can take root and outcompete your intentional planting.
Wood Chips
If you want to mulch your pathways, wood chips are an easy and affordable option. You can choose from a variety of materials including cedar chips, pine bark nuggets, and shredded hardwoods. You may also be able to find free wood chips by contacting your city’s green waste department or connecting with an arborist.
When applied in a thick enough layer, wood chips prevent weeds from growing, protect the soil from erosion, and limit the amount of mud in your pathways. As they decompose, they add organic matter to the ground. You will need to add more wood chips every year to compensate for this decomposition.
Landscape Fabric
Landscape fabric is an affordable and long-lasting option for weed control, but it is made from plastic and eventually needs to be replaced. If you choose to add landscape fabric to your pathways, it’s best to lay the fabric before you place your raised beds. This prevents weeds from growing in the space between the edge of the landscape fabric and your garden planters.
Add Your Raised Beds
After you’ve completed the above steps, you’re ready to add your raised beds! Place your beds on the ground and make sure everything looks good. If you notice there’s a gap between one edge of the bed and the ground, take a moment to level the ground so the entire bottom of the bed is flush with the ground.
Once your bed looks good, it’s time to fill it with a suitable material and get growing.
Final Thoughts
No matter what type of space you’re starting out with, properly preparing it for a raised bed will make the setup and installation process much easier. And that means you can focus on what you’re really interested in—growing healthy plants.