Depending on how high you raise your bed, it can be too expensive to fill with soil. I make my raised beds from semi-truck and tractor tires, stacked three feet high. The bottom part I fill with rough cut brush and twigs, the middle part I fill with shredded carboard, paper, woodchips, straw, unfinished compost, raw manure, etc... and then I just top it off with soil, and soil amendments. It will compact the first couple of years fairly severely, but after that, you just keep layering on more organic material, and it keeps making new, rich soil. You can make raised beds out of rock, cement blocks, wood, anything that suits your purpose, as long as it won't leach into your soil (no green pressure treated woods, for instance, or railroad ties)
Do you want fancy bordered raised beds, or non-fancy borderless beds like what I've got?
I just mound up my available organic matter (usually I use layers of greens, browns, and/or undone compost) on top of my no-till garden beds, then plant my transplants through it. I usually use at least 1-2" of good rich garden dirt or mature compost on top to guarantee good seed germination for my crops.
There is also the Mel Bartholemew(sp?), "Square Foot Gardening" method. His way is to have only 6 inch deep beds made from 1x6 planks and fill with a soil less mixture of 1 part compost, 1 part vermiculite, and 1 part peat moss. This is how I got started gardening. We grow rocks where I live, it is impossible to dig into the ground. I just began with one 4x4 ft raised bed and kept adding compost as needed. This year I am expanding and am going to also try the "Lasagna Gardening" method. I started in the fall with a bed around the cherry tree we planted when my daughter was born. Planted a bunch of bulbs. Will see how it works out.
My beds started out as 'pits' 12-18 inches deep dug out of the hardpack ledge behind the house. Over the years the beds now look the way Captain Compost has his,informal and raised up with organic matter. Woodchip + pine needle pathways. I don't like the look of wood framed beds in my garden...too stiff and formal.
"Maybe one of the secrets of survival is to learn where to dance." Stanley Kunitz
Posts: 892 | Location: New Hampshire Z4 | Registered: February 11, 2002
My husband likes enclosed wooden raised beds but I like the open raised beds. We also like to cover our walk ways with woodchips and sawdust which we have alot of. It serves two purposes, it keeps the mud off our shoes and provides garden dirt. In the spring I can just throw all the walk way decomposed material on the beds and start all over again.
I chose to make a formal east-west rectangular raised bed out of concrete block, two courses deep, since I wanted to line the bottom with wire mesh to foil the gophers. I painted the outside of the blocks with stucco/masonry paint to make it blend better with the rest of the visual elements out back. Inside the bed (about 4 x 24 feet) I layered sifted garden dirt, horse manure, fallen leaves, and coffee grounds/paper filters from St*rbucks, with some all-purpose sand mixed in to improve drainage.
As I dig around in the yard, I also relocate all worms to my "worm reservation" and they seem to be flourishing there. I left the layers for most of the summer and noticed that they condensed to about 75% of the original volume. Once there were no longer any recognizable leaves, I mixed it up with the shovel and planted veggie bulbs and seedlings. Winter crops have done pretty well, and I'm starting a second bed. I chose the 8"-thick concrete blocks so I can fill and plant them (holes oriented vertically) with the more invasive herbs and garlic, to ward off scent-sensitive pests.
I thought I could get away with topping the dirt with 2" poultry mesh, to discourage the neighborhood outdoor cats from using my nice loose dirt as a litterbox, but it's difficult to weed and plant through that, so I gave the cats their own sandpile elsewhere.
An earlier effort at a raised bed, with wattled walls made of woven small mulberry branches, ended before the walls were high enough to plant because I ran out of branches. I may resume that effort next time we trim the trees back.
I had some partially decomposed 2x6 lumber from the previous owner's attempt to create beds, but since it was fairly well rotted after less than 3 years, I decided to use something pretty permanent and save myself the trouble of re-doing the beds so often. I was offered free RR ties by my neighbor, but am not comfortable eating anything that grows in soil that's soaking up the creosote and other unappetizing things in that wood. I used the 2x6's to build up a large compost pit, stacked up like Lincoln Logs.
I recently bought a property that has a dramatic, terraced slope in back. The terraces, which were built at least 25 years ago, are shored up with railroad ties and rock. My husband wants to tear out the ties and replace all with rock. I'm thinking of using the ties for ornamental beds or borders in the front yard (or along the neighbor's driveway to keep their renters from driving on my lawn).
I'm thinking, from the feedback on rr ties, that I should make a very conscious effort to keep them away from any edible crops. Does anyone else use ties for ornamental beds or anything else? I was tempted to use them to build a permanent compst station, but that sounds like it might be a bad idea too. Is there any hope/use for old ties?
The raised beds I built for the community garden out of 2 x 6's took about 1/4 yard of "topsoil" each at $19.00 per yard if I picked it up. Delivered it is still $19.00 per yard in 10 yard loads, but if less is wanted there is a delvery charge added depending on the distance it is hauled, but about $35.00. This "topsoil" is from an old riverbed (was a celery farm for years) with a lot of sand and some organic matter. There is also a place that makes "topsoil" from a "secret recipe" that is mostly sand and organic matter although I have found bits and pieces of fiberglass insulation in it, as well as cigarette butts. I'd be very careful of what is being sold as "topsoil" and make my own from what I have and lots of organic matter.
I used rough cut 2x6s for my beds. Next year I plan to sow some hardy-clover in the walkways. They'll survive the foot traffic and will get tilled in when the boards rot away in a few years. At which point I'll start the whole process over with new beds.
Tires decompose like all soft plastics, releasing toxins. Do a search on the web, easy to find sources. Very nasty to plant food inside of.
Railroad ties are coated with a preservative that causes neurological damage. Bad idea.
I'm still rooting for the 'native stone' and cement block ideas -- they stack neatly, don't rot, leave a place to sit (tho they may wear out jeans) and look good.
Try to think about what's going to be in your pathways -- lay down thick newspaper and mulch? Gravel? Cover crop and make sure your paths are just as wide as your mower?
Tires do NOT release toxins into the soil unless they have been shredded or damaged. I had my soil tested several times when I started using them and never had a single incident of positive testing. Reusing undamaged tires is a much better way of recycling them than sending them to be burnt.
I too have a few questions. On time frame of decomposing organic matter in raised beds:
ONE: If I make some raised beds and fill them now with 1) the city's compost,called "prairie stash," including bison manure and everything else, which tends to be seedy, and 2) coffee grounds,
and cover them with plastic, any chance I would be able to plant in 2 1/2 months? I need to kill the seeds in that prairie mix. I would be willing to compost the coffee grounds elsewhere...but without the city's "compost," I will probably not have a garden this year.
TWO: If I layer organic matter like twigs, brush, etc. in my raised beds, when do I start doing this so it will compost? I can't plant stuff in there with un-decomposed twigs and all that stuff, can I?
Yes, you can plant in uncomposted matter, but the results are uneven. I did that out of desperation when I started my berm...just a mound of fresh wood chips and manure. In some places the plants thrived, in some they didn't do so well, so I had to spot amend them, and they perked right up. What I did with mine was to layer a third of very rough stuff (branches, twigs, chunks of organic material and some gravel), cover that with a third of straw, unfinished compost, manure and woodchips, and then topped it off with enough soil to start seeds in and give root veggies a good start. The rough stuff rotted down rather dramatically, leaving the soil level reduced by one third by the end of summer, when I had to chop up the plant matter with a bunch of leaves and top it off with a little soil again to plant my fall crops.
Think about it...what does mother nature seed herself into? Freshly laid organic matter, like fallen leaves, falling plant detrius and partially rotten fruits of all sorts. You just get more reliable results when you use soil along with it.
