Things You'll Need

• Forms for your raised bed (Consider using 4" x 4" (10cm x 10cm) posts cut to 24" (60 cm) in height for corners and 2" x 12"(5 cm x 30.5 cm) pieces for the sides)
• Nails or screws
• Hammer or screwdriver
• Compost
• Soil
• Seeds or plant starts
• Shovel
• Rake
• Barrier (plastic liner or similar) to keep weeds out
• PVC Piping and greenhouse plastic (optional)
• Composted manure (available at nurseries or from farms)

Steps

1. 
   
   Visualize and then design the shape of your raised bed. Luckily, a raised bed doesn’t take much! You basically build an open topped and open bottomed box, and you can do it in any shape that you want. Think of yourself as building a form to pour soil into (like one might pour cement or plaster into a form).
2. Draw your planned bed, measure your available garden space, and add the measurements onto your drawing. Now you’ll be able to determine how much material you’ll need to build the bed.
3. 
   
   Decide on what you want to make your raised bed out of. You can use just about anything that will hold dirt. You can use lumber, plastic, synthetic wood, railroad ties, bricks, rocks, or a number of other items to hold the dirt. However, using lumber is generally the easiest and most efficient method. This article will focus on making a raised bed out of lumber or synthetic lumber.
4. 
   
   Gather your needed supplies. A full list of supplies is below above things you will need. All that you really require are sides cut to your desired length and at least 24" (60 cm) in height. If you want a triangular raised bed, you will need three sides. If you want a square bed, you will need four sides of equal length. For a rectangular bed you need four sides, with two of one length and two of another. You get the idea!
5. Connect the sides of your bed together to form the shape of your bed. If you are using lumber, consider using 4" x 4" (10 cm x 10 cm) posts cut to size to serve as the corners of your bed. Then, you can simply nail or screw your sides into the corner pieces. This method will increase strength and help ensure that your raised bed stays together once dirt is placed in it.
6. Cut a piece of gardening plastic or weed mat to fit as a footprint to your raised bed. By putting a barrier down first, you will significantly reduce the amount of weeds that will grow in your bed.
7. Place your raised bed form over the footprint (this might take two people, depending on the size of the bed frame and the weight of the supplies used). Make sure to pick a place that will get plenty of sunshine. Remember, your bed will be somewhat permanent, so place it in the best possible location.
8. Once your bed is in its permanent position, fill it with soil. Add some composted manure into the bottom of the bed and then layer potting soil on top of the nutrient-rich compost. You can cut costs significantly by using some soil (up to 50%) from other parts of your property. Plan on filling at least 1/3 of your raised bed with compost or composted manure (available from nurseries or garden centers in 40 pound bags).
9. Mix in dry organic fertilizers (like wood ash, bone meal, and blood meal) while building your bed. Follow package instructions.
10. Decide what you want to plant and get dirty! Some people like to grow flowers in their raised beds. Some prefer to grow vegetables. The options are nearly limitless. If you do want to grow food, raised beds are excellent choices for salad greens, carrots, onions, radishes, beets, and other root crops.