Last week, I introduced you to the benefits of raised bed gardening. This week, I want to focus on how to build a raised bed garden the right way, which covers the wood, frame, and soil. As you know, I’ve been growing my garden for 3 years now, and it’s been a peaceful journey planting every seed and going through the entire process of gardening. I hope these steps will inspire you to start your own raised bed garden.
How to Build a Raised Bed Garden the Right Way
The first step in creating a raised bed garden is to decide how large you’d like it to be. It should be no wider than 4 feet, so you can reach comfortably to end to plants from both sides, but it can be as long as you’d like. Most people stick with 4×4 foot plots, and you can do many 4×4 foot plots or one 4×12 or 4×20 or whatever you want!
You can build your frame out of standard lumber. 2×6 lumber is good enough for a frame that will house shallow-root vegetables such as radishes, lettuce, and spinach. If you want to grow larger vegetables like corn or tomatoes, you’ll need 2×12 boards, so your soil can be at least 10 inches deep.
Opinion varies on whether or not you should use treated lumber. If you use untreated lumber, it will rot within a few years and you’ll have to start your garden all over from scratch. If you use treated wood, it has a small potential to leech toxic chemicals into the soil which might be picked up by your plants and passed to you.
If you want to be on the safe side, you should stick with untreated wood. But treated wood is very convenient, and many scientists claim the chances of anyone actually being harmed by the small amount of chemicals that might leech into the soil would be minuscule. This is a personal choice, so whatever you decide is right for you is just fine.
You should have your lumber cut for you when you buy it. You need the lumber ends to be perfectly even so soil won’t leak out once you put your raised bed together. This is extremely difficult to do yourself unless you have a large saw. A circular saw or handsaw probably won’t cut it.
You’ll need to use three 4-inch ribbed deck nails at each joint to put your frame together. Other types of deck nails just won’t hold tightly enough to ensure your bed won’t fall apart until the pressure of all that soil and plant material.
You should assemble the frame on a flat, level surface, not directly in the garden if you can help it. Your frame will be much sturdier if it’s assembled on your deck or driveway. Then you might require help moving it to the garden, as it will probably be heavy.
You should leave a minimum of two feet between boxes, preferably three feet. You need enough room to move around comfortably. Be sure to choose a good location right from the start, because once they’re filled with soil, they’d be impossible to move without emptying them!
You can dig up or till the soil underneath the frames if you wish, but it’s generally not necessary. Most plants will grow just fine in the 6 or 12 inches of soil inside the frame, and they should be able to push through the ground if they really need to. As long as you provide very high quality soil with plenty of organic material, your plants should never need to shoot roots down past those 12 inches.
Your soil should be the highest quality soil you can manage. You can purchase commercial potting soil, but it generally won’t be high enough quality. You should add more organic material to this soil. You can use homemade compost, composted manure, or other rich organic material to make the soil you use the best possible quality.