I need advice on the ingredients of a raised bed garden. I can found quite a bit of info on what materials to use to build the box, but not much on the required layers for the raised bed. Terri V
Shouldn't be any layers, other than good topsoil dumped on top of soil that is already there (with a mulch afterward, except where warm season vegetables are being tried in a cool summer climate).
Thanks for the tip. But I heard somewhere that there should be mulch, soil, gravel and even some shredded up newspapers. I think the person called it a lasagna garden because of the layers. I am thinking of having this built beside an existing patio for a senior supportive housing unit. The residents love to garden, mostly with flowers. But many have mobility issues. So I thought the raised bed could be reached from a sitting or standing position, without bending over. Plus the patio would be more stable to walk beside with their walkers etc. Another question, would the soil requirements be different for flowers as opposed to vegetables? Terri V
I feel that the lasagna gardening is just snake oil. The pitch is that you will get great results with little work. This is a concept that always raises a red flag with me. The idea that you should plant into an active compost pile doesn't seem logical. How can that be superior to planting in soil that has evolved since the last Ice Age into a stable material? I think that Ron's suggestion is correct. Fill with soil and then dig in an inch of compost. This should give you a good base. Depending on the vegetables or flowers, you need to fetilize as well.
Yeeehaaaa cowboy! Finally someone who doesn't argue for pages that lasagna gardening (or some other unnatural scheme) is the gospel. There is nothing about burying layer(s) of fresh organic debris under soil that lines up with what is known about how soil systems work at all. Except where there has been some kind of disruption you always have this sequence and that is what plants expect to be growing in (or on): Fresh organic litter on surface Topsoil layer where fungi, bacteria, worms etc. are processing the organic litter Mineral soil layer where the parent material is being made into soil by the processes at work on the site Parent material, that may not be soil per se on some sites such as dunes or rock formations All of the above blend together where they meet. Most of the action is near the surface, where most of the air and all of the fresh litter is. In some ecosystems most small flowering plants are not growing in the ground at all, but rather on logs, rocks or living trees, where they are growing in the moss and litter (or nearly bare branches) that coats them - same as if they were growing on the ground, in the zone where litter is being processed.
Lasagna gardening is aka sheet mulching... and quite a bit different from a regular raised bed; it's layers of compost, wet newspaper and cardboard (clean of course, no tape etc), manure, soil amendments like lime, straw etc. (I don't think gravel was mentioned.) The ground under it can be grassed, but you cut it - no tilling - before you put down your layers. The end product is about a foot or more thick but then you leave it to do its thing for six months or so. Theoretically the grass way down underneath doesn't have enough light to grow, it all composts down into a primo growing medium. I have a book on permaculture called Gaia's Garden that explains sheet mulching in detail. There are drawbacks, like slugs and weeds. I tried building my first small one last fall, I think maybe strawberries will be going in there. So I can't say yet how well it works. But cowboy is correct in that this is not easy, I found it to be a lot of work. I only tried it because I had the materials and a corner in the garden where the ground was kind of tough; I didn't have a whole lot of extra topsoil to spare.
In other words a compost pile on top of the ground. When you turn a compost you aerate the ingredients and blend them together, so that the whole starts to become like a litter layer (and processing zone just below) in a natural habitat.
I think the original purpose of lasagne beds was that it was a no-dig way of creating a bed where grass or weeds are presently growing. It suffocates what's underneath while allowing new growth to proceed immediately. If you are building a raised bed on grass there may be some rationale to putting down a layer of cardboard first, but if there is no grass or weeds to suffocate, then just use dirt. Anything else will compost down over time so you will have a sunken raised bed!
Grass can be eliminate easily. This is my method- with the proper tools. http://meuho.notlong.com/ 26 October 2007 Sod Busting Ths sod was removed from around the Rose of Sharon bushes. The purpose is to improve the growing environment for the Rose of Sharon roots by removing the grass competition. First the sod was cut using the kick type sod cutter. The sod was hand pulled apart and put through the chipper\shredder, and blown back onto the area from which it was removed. From past experience it was found that the grass roots are effectively destroyed, and absolutely no grass grows from the residue. The area was edged, lightly rototilled, raked smooth and covered with wood chip mulch. No amount of rototilling will eliminate grass sod; in fact, the grass will be present for years if this method is attempted..
Good advice... but if one goes to a garden centre and asks for "good topsoil". They may not get the right kind depending on the sales person there that will be saying: "yeah this is good stuff" when it is not.