Starting a raised bed garden can be an expensive prospect. You can buy a ready made kit, many of them topping out well over $100 per bed. I make my own raised beds, read on to see how you can make a raised garden bed for under $30! It’s easy and doesn’t require any special equipment aside from a screwdriver and a saw. I have several size beds in my garden, but I have found that 4 ft x 8 ft is a great size, big enough to handle lots of plants, even the big ones like tomatoes, corn & sunflowers. The bonus with a 4×8 bed is there is no waste when you use 8 foot boards! I use untreated pine boards. If you have the budget for it, cedar is the best choice as it will resist rot & insects better than pine. But it’s also very pricey. My oldest pine garden beds are 7 years old and still holding on. Yes, there is a little rot around the edges, but they are still holding dirt so that works for me. You can use most any wood, metal, plastic, stone…just make sure you don’t use pressure treated lumber. The chemicals used in the treatment will leach into your soil and contaminate your plants. For this DIY article I will be using 2×3 boards, but you can see in my garden that some of my beds are made of stacked 2x4s, some are stacked 2x3s, some are 2x12s. I try to use what I can find. You want the final bed to be 10-12 inches deep.
First prepare the area where your bed will be. You can put down a layer of weed cloth to keep weeds from popping up in your bed. Some people put down a layer of cardboard to smother weeds underneath. At the very least, remove any grass or growth and loosen the soil.
12 pine boards 2 in x 3 in x 8 ft
2.5 inch or 3 inch screws (about 50)
scrap wood for supports (I used 2 in x 2 in boards)
Separate 4 of the pine boards and cut them in half, so now you will have (8) 4 ft boards and (8) full size 8 ft boards
Put two screws in each corner to build a rectangle with two 8 ft boards and two 4 ft boards
Make four of these rectangles
Stack the four rectangles where you want the garden bed to be, it’s ok if the boards are a bit warped and don’t line up fully
Use a scrap wood brace in each corner and in the middle of each 8 foot side (this will stabilize the bed and bring all the boards into alignment)
Filling your raised bed
This can be where the real cost comes in. If you are resourceful it doesn’t have to be though. If you have a large compost pile this can help, but this bed will require about 27 cubic feet of soil (or 1 cubic yard) to fill so you would need a really big compost pile to fill this. Check with your local municipality or farm extension. Many towns offer free or low cost compost to it’s residents, although you often have to be able to transport it yourself. Local farms or garden centers will usually offer good quality compost and often can deliver it right to your house. Whatever option you use make sure you use a good quality compost. Do not get topsoil or loam, and make sure the compost has been screened so you don’t end up with a bunch of weed seeds along for the ride. With intensive gardening styles like square foot gardening your plants will require a lot of nutrition so using a cheap soil will hurt you in the end with poor plant growth. Bagged soil at garden centers is generally going to be cost prohibitive to fill a bed this size. To buy good quality bagged compost it could easily cost you $140 or more to fill this bed, where you could get a yard of compost delivered and support a local farm for $25-$30.