Search The Rusted Garden Blog: Just Enter A Vegetable or Phrase

Thursday, July 28, 2011

How to Create a Raised Bed Vegetable Garden

This is from 2009 and it is the first article I wrote for Google Knols. It is time to start planning next years garden. Perhaps raised beds?

It can be be viewed directly at this link: How to Create a Raised Bed Vegetable Garden

How to Create a Raised Bed Vegetable Garden

By Gary Pilarchik LCSW-C

For up to date gardening tips and ideas visit my blog the  The Rusted Vegetable Garden

What Do Raised Bed Vegetable Gardens Look Like?

Pictures are truly worth a thousand words and this is my opportunity to show off some of my vegetable garden.
March 2009.  My cool weather crop plantings. Check out my Knol on that topic.
The same beds in May 2009
These are some basic raised bed garden designs. Nothing fancy, just framed beds. The first three boxes starting from the back of the picture are 4 ft. x 8 ft. The fourth box is 2 ft. x 8 ft. and the box to the left is 4 ft. by 4 ft. The wood used to frame the boxes is from Home Depot. It is pressured treated with copper NOT arsenic. The boards were all  8 feet long and I had them cut at Home Depot to the size I wanted.

What Are The Benefits of Using a Raised Bed?

  1. Higher vegetable yields: You will get 2x's the vegetable production out of a raised bed than a standard flat earth bed. You can plant vegetables closer together because of better soil conditions.
  2. Better soil: You can add garden soil, organic matter and all the other good stuff to your raised bed. Soil compaction is greatly reduced because you never step in the bed. Soil compaction inhibits plant growth, oxygen uptake and water circulation.
  3. Better drainage: Your raised bed will drain quickly and be less prone to staying soggy and promoting disease and rot.
  4. Better air circulation and more sunshine: Raised beds tend to get better circulation and more sun depending how you set them up. Air circulation helps cut down on plant diseases.
  5. Better water conservation: You only water where the vegetables are growing. You can also install slow drip soaker hoses in the bottom of your raised bed garden.
  6. Easier pest and weed control: It is easier to fence in your raised bed garden if there are animal problems. Weeding is easier and because you can plant more plants in a raised bed garden, they tend to shade out weeds.
  7. Earlier start and later finish: You can start gardening earlier because raised bed gardens warm more quickly in the season when compared to a flat earth garden. You can garden later into the season because raised bed gardens stay warmer as Fall arrives.
  8. Easier to tend and manage: You can raise a bed up to two feet. This requires less bending. Once the soil is prepared little work is needed to maintain it. Since you don't step in it, the soil stays loose and workable all year round. It is also easier to reach in and tend to your plants and pick your garden produce.

  9. Saves time and money and they look great.  Your cost over time diminishes. It costs money to build the raised beds initially but you save money over time by only concentrating resources to where the vegetables are actually going to be grown. You save yourself time by only working the area that will actually grow vegetables. They look good and really help create an organized garden. Less mud too. You can mulch between raised beds for a clean working area and you will never have to step onto muddy garden soil.

    March 2009. Notice my soil has a lot of clay in it. Over time I'll amend the soil. Plants still grow

What Kind of Wood Do I Use?

I use pressure treated wood. It will last seven to ten years or longer. You can use wood that isn't pressure treated but it will decay and need to be replaced in about three years. The biggest controversy, years back, was whether or not pressure treated wood had harmful health risks. This argument was a legitimate argument when pressure treated would contained arsenic. Most pressure treated wood now uses copper and NOT arsenic. Check with you local lumber yard and ask what chemicals are used to pressure treat the wood they sell. You can do a web search on the health risks of pressure treated wood.

What Size Boards Do I Get?


The length of the board I recommend is an 8 foot board. This length is perfect for a planting row and if you cut the board in half you get two 4 foot boards. That creates a perfect dimension of 4 ft. x 8 ft.  The boards I use are 6 inches wide. I recommended a minimum of 6 inches for your sides. You can go up to 24 inches for the sides of your raised bed garden. According to research 6 inches provides enough height to improve soil warmth and gain drainage benefits.  I do have beds were I stacked two frames on top of each other to create 12 inch sides. I use this for my cold frame. If it is more difficult for you to bend or reach, higher sides is the way to go. You can always add another level when needed. Board widths vary from 6 inches to 12 inches. If you want the sides to be higher you will need to stack frames.


Why is 4 ft. x 8 ft. the Perfect Dimension?


If you stick out your arms you have about a 2-3 foot reach. If you were to walk around your raised bed garden you could reach in from all sides and tend to the garden without every stepping into the box. That is one benefit of raised bed gardening. The garden soil stays loose all year around because you never step on the soil  that supports the vegetables. Compacted dirt harms vegetable roots and prevents your plants from growing. You don't want to build a frame where you have to step onto the soil to reach the middle of the framed area. That defeats the purpose of a raised bed.


Building the Raised Bed Garden Frame


I want to keep this simple. Often to much goes into perfecting the construction. It doesn't need to be perfect. To build the frame you need wood, 3-4 inch deck screws and a drill. Do not use nails. They tend to get pulled out of place if the board warps.


  1. Decide on the frame sizes.
  2. Purchase the wood. Let's assume you decide on two 4 ft. x 8 ft. frames. You will need to purchase six 8 foot boards. They should cost you $5 to $7 a board depending on where you live.
  3. Get the wood cut at the store. I suggest going to Home Depot or a place that will cut the wood. You should ask to have two 8 foot boards cut in half. That will give you four 4 foot pieces of lumber. You now have all the sides for two raised bed garden frames. 
  4. Purchase a box of 3-4 inch deck screws. I suggest 4 inch screws. You will need 24 screws to build both frames.
  5. Drill 3 pilot holes (see pic below) on each side of the 4 foot pieces of lumber. The drill bit should be smaller than the width of the screws you are using. You do this to prevent the boards from splitting when you put in the screws. You will need 24 holes for 24 screws.
  6. Change bits on the drill and screw the frame together. Build the frame on the ground without the screws first and then just walk around to the holes and secure the frame.
  7. You now have a secure raised bed garden frame.

Preparing the Site for the Raised Bed Garden


I want to keep this simple too. Your garden will grow no matter how you prepare the soil and over time you can perfect it. You will need a level. It helps in making sure the frame is (well) level. If you don't have one, you can use your eye.


  1. Drop the frame where the garden is going to be. I will assume you know to select a sunny location. You can use spray paint, dirt or even flour to trace out the frame. Once you trace out the frame, move the frame to an out of the way place.
  2. Dig the grass out. I wouldn't spend much time banging clumps. You will be buying soil. Just dig down enough to get the roots and remove all the grass. I bag my yard waste and set it curb side.
  3. Now that you have a grass free space, put the frame back on the garden plot. Use the level and a hand shovel to make sure the frame sits level on your garden plot. You may have to move dirt around to raise or lower parts of the frame. It doesn't need to be perfect. Your site is prepared.

What Do I  Need to Buy to Prepare the Garden Soil?


I am going to give you the supplies for one 4 ft. x 8 ft raised bed garden. The sides for this example are 6 inches. If you make 12 inches sided frame you will need to double the bags of garden soil. Just double the bags of garden soil, nothing else. This is enough to get your started and on your way. You can add grass clippings and other organic matter over time. You don't need perfect soil to start.


  1. 8 bags of garden soil in the one cubic foot range. More is better. Make sure you buy garden soil and not top soil.
  2. One 8 foot cubic bail of sphagnum peat moss.
  3. 1 bag of the cheapest 10-10-10 (or close to that) bag of fertilizer. This is enough fertilizer for many raised bed gardens.
  4. 1 bag of pulverized lime. This is enough lime for many raised bed gardens.

Preparing the Garden Soil


Keep in mind your soil will get better over time and vegetables will grow in most soil. Perfection is not the goal. With these amendments to your plot, you will have no trouble growing vegetables.


  1. Open the bag of sphagnum peat moss in the middle of your framed bed. Do not rake it yet. Sprinkle in four cups of pulverized lime over the pile of peat moss. Take precautions not breathe in the dust. Mix the peat moss and lime together and rake it evenly over the plot. Peat moss can be acidic. Lime is alkaline. Mixing them together helps balance the PH. You don't need to test your soil.
  2. Sprinkle three or four cups (8 ounces per cup) of fertilizer over the raked peat moss. The fertilizer will get turned into the earth. 
  3. Turn the peat moss and fertilizer into the existing soil. You are not adding the bags of garden soil at this time. You are creating loose earth below the frame of you garden plot. This is the benefit to raised bed gardening. You will have loose soil to at least a depth of 18 inches depending on how high the sides are to your raised bed. Make sure your break up any large clumps. The peat moss provides organic matter that will hold moisture.
  4. Open four bags of garden soil and rake it evenly across the surface of your raised bed. You want to turn the earth again making sure your not standing in the garden. You should do this from outside the frame. Turn the bags of garden soil into the earth. Extra effort to dig deep and turn extra earth is worth it at this point. You have now created good quality soil at deep root growing depth. You have mixed the the standard earth in your area with peat moss and garden soil. It's been boosted with fertilizer
  5. Open the remaining four bags of garden soil and rake it evenly across the surface of your raised bed. Sprinkle one or two more cup of fertilizer evenly across the entire surface of the garden. Mix the bags of garden soil in with the existing earth to about 10 inches. You don't need to go as deep. You are making a well amended 10 inch level of soil for seed planting.
  6. Rake the garden even and break up clumps. Don't worry if your soil doesn't come to the top of the wood. Over time you will add grass clipping and other things. Do it at your leisure or when organic matter is available. It's ready to be planted.

March 2009. The center garden plot is also a raised bed.
It is mounded. Raised beds don't have to be contained.

Planting


This Knol focuses primarily on building the raised bed garden. You can plant in it as soon as you build it. A raised bed allows you to start planting earlier in the year and it allows you to continue planting later into the year. The idea is the raised bed warms quicker and stays warmer longer. Warmth is good. You can also plant vegetables closer together because you don't walk in the garden and compact the soil. Loose soil allows plant roots to grow deeply into to earth. The deeper the roots can grow the closer the vegetable plants can be planted. Good luck and look for a future Knol on planting in raised bed gardens.

logo with tomatoes - $20 Off Purchases $40 Or More!Spring Hill