I am not exactly a beginning gardener, but I still think this is the place for my question. As I have stated numerous times on this site, I have a series of raised bed gardens that are made of old tree trunks I got from blown down oaks and hickories from a very powerful storm back on May 8, 2009 (if you type in “May 8th storm”, Wikipedia has an article on it). These beds are now the home to my wine cap mushroom inoculated wood chips. These logs were old and decaying before I started my mushroom compost project. Now that the wine caps are starting to really take off, the logs can’t possibly last much longer. There are some logs that I don’t think will last the year, and I have a very hard time believing I could get two more years out of even the best logs now that the wine caps are flourishing.
My question then is what to use to replace the logs for the edging of the gardens? I obviously don’t want to go and cut down more trees for garden edging. I have ruled out cement blocks as I (and my wife) don’t like the aesthetic. I am teetering between cedar boards and composite 5/4 decking. I know the 5/4 decking is not terribly “permie”, but I think it would be more durable than the cedar. I don’t think I would have any problems with chemical leaching (any more than I would if I were to grow in a plastic container). Frankly, the biggest reason holding me back is the cost of the decking at this point (bear in mind, I am talking about the semi plastic, artificial decking, not treated lumber).
Does anyone have any other ideas out there that are affordable, resilient, and safe for gardening? Or does anyone have concerns about the 5/4 decking?
I've though about making thin concrete panels from a mold. Maybe 1.25" thick x 12" tall X 4' long using the 6x6 concrete mesh with eye bolts welded to it on the ends, sticking out at a 45 degree angle so that when the panels are standing up, the eye bolts would line up with the next panel for driving rebar down through and into the ground. The mold could be textured and maybe put some concrete stain on the outside. They make concrete molds with stonework patterns for walkways. The panel size above would weigh about 55lbs but wouldn't be moved often. The eye bolts could be on the inside.
Concrete's not enviro friendly but these things would last a couple of lifetimes and it wouldn't take much concrete.
Cedar will last some years. The sap wood tends to rot pretty quick in contact with soil. The 5/4 composite boards are part plastic but I don't know if anything would leach into the soil.
I've used large rocks but they kind of get in the way. I ended up tending to want to kneel on them to be able to reach things and the rocks here aren't smooth by any means.
I used some regular 2x6s one year. That's as long as they lasted.
I'm not good at making things pretty, much less on a budget.
My only experience with composite deck boards is being paid to remove and replace them.
I kept them and used them for walkways and raised beds.
I have found them to be fragile as walkways.
Maybe a cedar frame with an infill of corrugated steel orhardboard Hardboard weathers quite well even laying directly on the ground, and it's really cheap.
Since you don't fear plastic, you could build with cheap untreated lumber and line it with plastic sheet.
Or you could line it with cement backerboard, I have one like that, but I got the board for free.
Treating the lumber with natural methods is another choice, borax,linseed, and charring are all discussed here on Permies.
Ferrocement is a very nice option, but it is labor intensive.
Stone is a lot of work, and its not clear you would like the look.
Maybe get a load of logs from a friendly tree guy and start anew?
I don't frame my beds. I also don't think that wall has to delineate my kitchen from my dining room or living room. I like a open floor plan design. But I get that it might not be for everyone.
I do use garlic chives for my borders on some stuff, it's like a living edge. But it is only a visual border. A slope will have to be used to structurally keep the mulch in place. I use a push mower and I dislike it when I run over mulch and it gets stuck in the push mower blade. So I usually end up having to hand weed near the edge but my 'lawn' is tiny and I keep it 3inch to 8inch (after and before mowing)
You might want to see if there are any locally owned sawmills in your area. I have one not far from my home where I have purchased 2 x 10's of Tamarack and Black Locust. I've had the Tamarack raised gardens for 5 years and they are still solid. The Black Locust ones I built this past year; they will probably outlive me. The best part is I paid less for them than if I purchased regular lumber at one of the big box stores like Lowes or Home Depot (which would rot in no time), and certainly much cheaper than cedar.
You are right that I don't technically need sides for the garden beds. I presently have two beds where the old logs just plain rotted away a couple of years ago and I turned them into the garden soil. What I have found is that I can mow and trim and generally keep weeds out better if I have sides to raise the surface of the bed up by about a foot or so. Also, I just like the look. When I had a lot (and really, I mean a LOT) of logs laying about, they were an obvious choice. I had to do something with them and raised beds seemed like the thing to do with them. However, I never really got the beds filled up until just recently when I filled the beds with wood ships inoculated with wine caps. The logs were in bad shape already (two beds already lost their sides and as of yet not replaced) and I am certain that the current ones--in poor shape and now being attacked by wine caps--will not last much longer.
I pretty much think I will go the 5/4 decking route unless there is some compelling not to.
Hi, Eric. I currently have a composite material similar to 5/4 decking around my raised beds and like it a lot. It looks natural-ish and has held up well over the last 5 years. With that being said, I think if I were in your position I would be inclined to scope out any salvage material stores in your area or the free section of Craigslist to see if you can intercept a useful material from heading to the dump. You may find something unexpected that could be re-purposed to do the job and save money at the same time. Or you may find nothing. Since you don't seem terribly picky about the material you use I think it's worth a try.