Making Raised Garden Beds Explained

Once you’ve selected your material, determine the size and location of your bed, ensuring it’s wide enough to reach the center without stepping in and placed in an area with adequate sunlight and water access.

For wooden beds, you’ll need tools like a saw, drill, tape measure, and level to cut and assemble the frame. Fill the bed with a mix of quality topsoil, compost, and other organic matter to create an optimal growing environment. The depth should be at least 8-12 inches for most plants, with vegetables requiring 12-18 inches.

I suggest adding features like irrigation systems and cross-supports for larger beds to prevent soil settling and side buckling. Remember to plan for proper drainage and soil compaction to ensure healthy root growth for your plants.

Key Takeaways

• Common materials include rot-resistant lumber (cedar, redwood), corrugated metal, cinder blocks, bricks, stone, and concrete.
• Choose a size that allows easy reach to the center without stepping in the bed.
• Depth should be 8-12 inches for most plants and 12-18 inches for vegetables.
• Fill with a mix of quality topsoil, compost, and organic matter.
• Ensure proper drainage and avoid soil compaction.
• Consider adding features like irrigation systems and cross-supports.
• Tools needed include a saw, drill, tape measure, level, shovel, and trowel.
• The location should have adequate sunlight and water access.
• Add cross-supports for larger beds to prevent soil settling and side buckling.
• Consider accessibility and height for those with mobility issues.

MATERIALS FOR MAKING RAISED GARDEN BEDS

The most common material used for making a raised garden bed is lumber but not all kinds of lumber can offer the ability to rot and pest resistance. Cedar, redwood, and juniper are good rot-resistant lumber options.

Then there is the option of buying premade raised beds or raised garden kits at garden centers and home improvement stores that are made from wood, and metal for these gardening containers. Raised beds that are made of plastic are an option, but they will break down into microplastics and may be absorbed by the container vegetables that you will be eating if the garden bed is for growing food.

When deciding on the materials being used, it is important to know that an 8 to 12-inch deep raised bed will be sufficient for flowering plants to take root. For growing vegetables, you will need a raised bed that is one foot to one and a half feet deep for their larger and deeper roots.

WOOD

Cedar and redwood are the best choices for rot-resistant lumber for wood-framed raised beds because these materials will last for 10 years before needing to be replaced and repel pests. Juniper is another rot-resistant lumber that can last for 10 years, but this wood has natural oils that leach into the soil and will help to fertilize your raised bed as a soil amendment.

Cypress will last for about 8 years and is resistant to pests and rot, but it may be difficult to find if you don’t live in the southern U.S. where it is grown. If you decide to choose Cypress, then you will have to place a custom order.

Pine is the most economical lumber for a raised vegetable garden, but it will last about 3 years and doesn’t provide any protection against rot or pests.

Pressure-treated lumber is another option, but it is not recommended for raised garden beds that will be used for growing food. Pressure-treated lumber uses toxic chemicals that you don’t want to leach into the soil. You can keep the wood from growing mold and mildew by spraying a baking soda and water mix on the wood to kill or prevent it from growing.

CORRUGATED METAL

Corrugated metal raised beds are a good economical choice for extra growing space or for creating a certain look with less worry about rot and pests. If you decide to use sheets of corrugated metal, you will still need to build a frame to attach the corrugated sheets. The two options available are lumber and metal studs.

They cost about the same, but the metal studs will never need to be replaced and can be purchased at any home improvement store. You can also buy corrugated metal containers that are as long as 6 feet and as high as 32 inches, or round.

These containers can be purchased at any garden center, home improvement store, or online retailer and they range from $60 to as much as $380 depending on the size of the container.

BLOCK OR BRICK

Cinder blocks for a raised bed is another good economical choice with no need to worry about rotting and pests destroying it. They are 8 inches tall, and they can be dry stacked without mortar if you like. Unlike the other material, you have an extra option.

With cinder blocks, placing the holes up is the only way to build a garden bed but it gives you the ability to fill those holes and plant in them. You can use them as a protective border around your vegetables by using plants like marigolds to deter pests or add an attractive border around a botanical garden.

Raised garden beds in brick can give a natural but elegant look around a home or in a yard. With many different styles to choose from, this is one option that can gussie up any area. Bricks will be more costly than cinder blocks, but they also offer a different look that may be desired especially with the right plants.

STONE

Stone garden beds are by far the best-looking material that will enhance any area that is used. Stone is the second most expensive material to use for a raised bed, but if it fits your budget then it is well worth it for the aesthetics and longevity, also it can help with the overall look of the entire design.

You can dry-stack the stone or use mortar to hold the stones together but remember that the mortar contains lime which will leach into the soil, making it more alkaline. Depending on the soil this may be helpful or you may need to increase the pH level. You can purchase a pH test kit or a pH meter to keep track of the pH levels.

Using stone has an added benefit because it is a natural insulator keeping the soil temperature cooler than any other type of material and it also helps to retain moisture in the soil. Using stone will eliminate the issues of rot and pests but it will still need to be cleaned. A low-pressure washer or a brush and water will be enough to clean any dirt off the stones.

If you have algae growing on the stone, spray the stone with vinegar and water solution to kill it, then you can pressure wash or brush the algae off the stone.

CONCRETE

Concrete is going to be the most expensive material to build a raised garden bed, but it will last the longest. A concrete garden bed is also going to be the most labor-intensive because a form has to be made, rebar needs to be installed for added strength, and after the pouring of the concrete, it will take 24 hours to set.

Precast concrete panels are another option that will reduce the time it takes to construct the garden bed. After they have been assembled, a piece of rebar is inserted into the four corners of the garden bed to hold everything in place.

TOOLS NEEDED TO BUILD A RAISED GARDEN BED

There are a few tools needed to build a raised garden bed such as a saw and a drill are indispensable for cutting and securing the wood pieces. A tape measure ensures accurate measurements for a well-structured bed.

A shovel and a garden trowel are necessary for preparing and filling the bed with soil. Lastly, a leveling tool ensures all sides of the bed are evenly positioned for optimal plant growth.

SIZE OF THE RAISED BEDS

When choosing the sizes of raised garden beds there are two things that you should consider, your budget and the desired look that you want to create. Accessibility should also be considered, as raised beds can be designed at various heights for those with mobility issues.

The height of the beds varies from six to twelve inches, and some people go as high as 36 inches. The width of the beds should be enough to reach the center without stepping in the middle of the garden. Square foot gardening techniques can be easily applied to raised beds for efficient use of space.

Raised garden beds can be any size but remember that the soil’s weight adds pressure to the sides of the frame. To avoid this, use cross-supports to avoid settling and buckling. Once these supports are in place, you can plant your plants. Consider installing trellising for climbing plants to maximize vertical space.

COMPACTION OF THE SOIL IN THE RAISED BED

When roots cannot move freely through the soil, they are forced to look for an alternative path which is typically a horizontal one. This results in a shallow root system, limiting plant nutrition which hinders growth, and a shallow root system can cause the plant to fall over.

Additionally, lack of aeration can destroy beneficial mycorrhizae, which is a fungus that helps plants flourish by improving the intake of nutrients and water in the soil. There are several ways to improve the compaction of soil for raised garden beds, including the addition of compost, utilizing a cover crop, or using gardening tools like a pitchfork.

IRRIGATING A RAISED GARDEN

There are a few options for watering your raised beds which include drip irrigation for water conservation, a sprinkler system, or water by hand. Unlike traditional irrigation methods, drip irrigation will help prevent soil waterborne disease. Furthermore, drip irrigation allows you to conserve water by watering your plants at ground level.

A sprinkler system is by far the easiest method of watering, especially when using it with a timer. Depending on your budget, you can install a permanent system using copper or PVC piping. The other option for raised beds is using hoses and sprinklers. If this option is used, then make sure to store the hoses and sprinklers to avoid sun damage.

Burying irrigation pipes for a sprinkler system is a must but you can also bury most of a drip irrigation system.

Watch for signs of under-watering, like brown dry leaf edges or slow growth. If you notice the plants wilting in the afternoon, they may be suffering from heat stress. Season extension techniques, such as using row covers or cold frames, can help protect plants and extend the growing season in raised beds.