Screwed the side back on to one of my raised garden beds. The screws keep pulling out, these things are kind of flimsy and I want to rebuild them someday when I have time. I'll probably be forced to as the wood crumbles. But for now it's semi solid again, with three inch screws this time.
When I gardened in home made raised beds at first, I set 4x4 cedar corner posts, just standing on leveled ground, 2x4 cedar stretchers between and cedar fencing along each side. The posts gave me something solid to screw into for a long time and the stretchers allowed me to replace the vertical fencing boards, one at a time, as they weakened. There was a lot of cutting of wood, but cedar was really cheap back then. Phosphate coated screws were also very cheap. Zinc coated would have lasted longer, but those have never been all that cheap.
Of course, I dug down about two feet deep for each 4x10 foot bed (easy to calculate area for nutriment additions, such as bone meal, blood meal and various phosphates) and back filled with pine tree cut-offs to compost over time.
Native soil here is limestone clay and can become a ten foot deep brick if not tilled well with lots of organic matter added.
Otherwise the soil is super fertile (just look at our magnificient forests here in Indiana!) with large amounts of iron and many beneficial compounds. Attract earthworms, fungi and bacteria with rotting logs beneath and nature takes over in a BIG way.
I went with cedar over redwood because it lasts longer, even though the redwood, being quite acidic, helps to neutralize the soil more.
I have no idea what your soil might be, but you'll have to have it tested yourself to know how to best proceed and which nutriment additions to make and which are "used up" by your growing specific plants in one spot.
Whatever you do, do not use any kind of "treated" lumber for any raised beds that you plan to eat from. Even though the treated lumber will last four times as long, some of the chemicals used to preserve the wood WILL leech out into the soil, contaminating your food. Not smart.
There are some man made composite materials safe to use for food growth, which last "forever." That one point has always troubled me about these materials, though. Kind of feels like we are trying to side step nature in some ways. My view, we've already proven time and again that we can't fool Mother Nature with our wit.
