Let’s say you’re building just one wooden-frame raised flower bed. You’ve decided on an 8×4-foot bed with a depth of 10 inches. You purchase three 2x10s at about $15 a piece, eight metal corner braces at a little less than $3 a piece, and a 1-pound box of wood screws for around $12. Assuming you already have the tools you need to complete the build, you’ll only be out around $80. Not bad! However, to keep horrors like arsenic from leaching into your soil, you need to purchase untreated lumber for your frame. Without pressure treatment to protect the lumber from the elements, untreated boards can begin to break down in just a few years. 

While there are easy ways to fix rotted wood, many of them don’t apply to wood that’s in constant contact with damp soil and all types of weather. If you need to replace the boards every five years over 20 years, you’re looking at a cost of $180 just for the lumber. This brings the total cost of your wooden bed to over $200 over its lifetime. For the same dimensions as the DIY wooden bed, there are inexpensive galvanized steel bed kits like this one from Home Depot that ring up at about $70. Assemble it and add soil once, and you’re ready to fill it with floral delights.

Source: housedigest.com