Urban Farming Toolkit: Building a Raised Bed — Part 1
Now that I’ve done my initial spring cleaning in the garden, I’m ready to tackle my next project: building a raised bed.
I’ve been growing veggies in the ground for about eight years, and our Virginia clay soil makes this difficult work. Each year I’ve tried to build a better base by adding compost and organic matter, which fills the soil with nutrients and improves the texture so it manages water better. So growing in the ground can work, and we’ve had some good veggie yields over the years. But it requires a lot of back-breaking work — I’ve spent countless hours digging, hoeing, shoveling, turning the ground, and hauling and mixing in good soil. This year I decided I’ve had enough of that, and so I’m upping my game, so to speak, by building a raised bed.
Raised beds are a great addition to any veggie garden, the primary reason being that you can control the quality of your soil. When you add good soil on top of the ground, your plants will have ample space to grow deep roots, which enables them to maximize their nutrient and water intake. Additionally, raised beds offer a host of other benefits, including:
Better water retention & drainage
Less soil compaction from human feet
Warmer soil for an earlier and longer growing season
Less soil erosion
Good barrier to pests such as slugs & snails
Reduced back strain caused by bending over to tend the bed
Additional sitting area along the edge, making for easier tending of the bed, or even extra entertainment seating.
It’s possible to build your own raised bed, and there are some basic steps to follow. Good planning is important, so don’t skimp on the early steps! Here are the steps I’m following to build our raised bed:
Step 1. Select a space. Considerations should include light, water, pests, and other environmental factors.
In general, vegetables need at least six hours of sunlight per day, so watch your yard, and find the spots that receive that much sun. Some veggies can make do with less sun — like cool season crops such as broccoli and lettuces — but other produce may not be as large or rich in color & nutrients as they would be with more sunlight.
The spot should be easily accessible from a water source (e.g., a hose), and it should have good drainage (i.e., don’t build it in a low-lying/swampy area, or on the side of a hill). Ideally you want your bed to have a balance of retaining the right amount of water to nourish the plants, but not so much that they drown.
Choose an area away from pests (e.g., deer, foxes, rabbits) if possible, or plan to build a barrier to protect your veggies.
Finally, select an area that gets good air circulation (to prevent fungal diseases), but is not too windy. A spot next to a fence (like the photo below) provides a natural barrier to wind and pests, and reduces the supplies & labor needed for building!
Our bed space is about 11′ x 4′, so that gives us about 44 square feet for planting, which is plenty of space for a wide variety of crops. In general, you don’t want a bed to be more than 3 or 4 feet wide, because you need to be able to reach in and tend to the plants without trouncing through it. In our bed, I do need to step into it to reach the back corner, so I’ll lay out my plantings in a pattern that leaves space for a little walkway.
The “Before” photo: This is the in-ground space we’ve been using for our veggies for the past few years, and where I plan to build our raised bed.
You don’t need a lot of space for a raised bed, which is good news here in Arlington! Our veggie space is about 11′ x 4′, inside our patio.
Step 2. Select a building material. The two most common options for building materials are wood and stone, and there are pros and cons to each.
Wood: Wood is relatively inexpensive, and easy to handle. You can buy pre-made kits — which are becoming more and more available at nurseries and home improvement stores — or you can design it yourself. If you do the latter, you’ll need to measure and cut the wood, and fasten the corners. There are lots of “build your own raised bed” plans online — this one is really simple. When selecting a wood, I recommend steering away from pressurized products (i.e., treated with chemicals to prevent rot), so the chemicals won’t leach into the soil, which would then end up in your plants, and thus in you! A good alternative is cedar, which is naturally rot-resistant. It won’t last as long as pressurized wood, but you’ll be able to preserve the organic nature of your veggies. Here are a few examples of wood beds:
Stone: The upside of stone is that it is durable and attractive. The downside is that it is more expensive and harder to handle than wood (i.e., it’s HEAVY!). You could choose bricks, natural stones, flagstones, pavers — whatever suits your taste and space. If you opt for stone, you’ll likely need to have it delivered (unless you own a heavy-duty truck), and you may need to enlist some professional help. And depending on the kind of stone you choose, you may need to use some kind of mortar or adhesive (e.g., Liquid Nails for exteriors and stone). Here are a few examples of stone beds:
Step 3. Gather your supplies. After researching your options and obtaining your building materials, make sure you have all the right supplies on hand. This could include:
Tools: This will depend on what materials you’re using — it could include screws/screwdriver, caulk gun/adhesive, trowel/mortar, hammer/nails, shovel/hoe, and the very important LEVEL.
Soil: A combination of soil builder, soil conditioner, and compost.
Sustenance: Sunscreen, water, snacks, and some good music. (I’m opting for Bob Marley and Jack Johnson — two of my favorite summertime guys.) This may take a while — we might as well be comfortable while we’re at it!
A good helper: It definitely will not hurt to have an extra set of hands on deck, especially someone who’s done this before. I’m enlisting my good friend and expert-wall-builder, Mariano, to help me with this project.
We’ve selected stone for our bed, so we also need paver sand for the foundation.
We’re using a combination of soil builder, soil conditioner, lobster compost and cow manure to fill our bed.
We’re now ready to start construction! In Part 2 of this series, I’ll continue through the steps we’re following to build our raised bed.