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tetrazzini

Neat frameless raised beds: how to?

tetrazzini
11 years ago

I don't use any kind of enclosure on my 30"x20' wide beds, but I try to shape them into a slightly raised form. When they get watered they get smooshed down to path level again. This year it occurred to me that I should dig out the paths a little and put that soil onto the beds to raise them up a bit.

My aim is to create something aesthetically pleasing as well as functional. I'm striving to get nice straight-edged beds that rise up over the neat, linear paths! I'm not sure what tools do use, or how exactly to do it. Any tips will be appreciated!

Here are my questions.

1. How do you create the berm? I'm thinking of edging the beds with a spade to get the edges nice and straight. I guess using a flat shovel to create a flat bottomed path would be the next step?

2. Is it realistic to think the mounded shape will stay put?

Thank you!!

Comments (19)

  • gardenlen
    11 years ago

    g'day,

    creating a berm sounds like effort and hard work like digging gardens in the first place.

    we use various methods for our raised beds but have never had any issues at all. our new raised beds will be edged with roof corrugated cladding, be as deep as the roofing is wide, so this time filling the beds is the challenge but we pretty much have that covered.

    len

    Here is a link that might be useful: lens straw bale garden

  • baseball9
    11 years ago

    Yes, shovel the dirt from the paths about 6" deep. You don't need dirt there, right? If you still want some more additional height, add some soil from some other source, or if you are ambitious and/or need some exercise you can double dig the beds, that will add some loft to them.

    I usually neaten them up as the last step. (1st step, dig or rototill, 2nd step dig out the paths, 3rd step add in supplements). Then you will have an idea of how much extra height you have to work with. You will want about a 45 degree angle on the edges. Decide where the edge of the path is, estimate how much ground you use up to get that 45 degree angle, usually about 6 to 12," then put a string across from end to end, (so the string is 6 to 12" away from the edge of the path).I usually put the string about 6" above where the top of the bed will be, so I can shovel and rake without getting tangled up in the string. It is usually a combination of piling up the edge of the bed in the middle, raking it flat, then repeating until it seems to sit well. There actually is a wide flat rake made for this purpose, but I just use a regular rake. Shape the narrow ends of the bed the same way, you don't really need string to do that.

    After you get the hang of it, it is an easy process. I like to dig the paths out as soon as I can so I don't compress the soil before I add it to the bed. If you use wood chips or other mulch on the paths do it after you do all of the bed shaping, otherwise you are raking woodchips into your beds. Not a tragedy, but it is a nuisance. If the soil still sinks down to the level of the path, you might need to add some extra organic matter.

  • chas045
    11 years ago

    In general, I agree with baseball9, but I'm sure that the particulars may vary depending on your soil. If you had a rototiller to go over everything, then getting the path down six inches is easy but otherwise could be too much. The piling method could again be adjusted. The old classic double dug method used rounded mounds. Since it was double dug, it allowed intensive methods with concentrated spacing. Perhaps that held the soil better than your last attempt.

    making a sharp edge is often done with a garden spade that is essentially straight accross the bottom with a D handle. the D is useful for double digging. I agree that moving path dirt would be best with the edged, flat bottom type shovel. However, I suspect that with any unsupported method, the edge will slip. Once you have plants all over, no one will notice.

  • tetrazzini
    Original Author
    11 years ago

    Thank you baseball9, this is exactly what I was looking for. My beds are 30" wide, spaced 18" apart, so the paths are 18" wide. What do you mean by "estimate how much ground you use up to get that 45 degree angle".

    I want the beds to actually have 30" of flat growing width. A steep drop off to the path would have more potential to wear down. So if I want to kind of feather it out to a 45* angle, as you said, that would mean the bottom of the bed where it meets the path would be a little wider than the top, so the paths would shrink to less than 18", right? A sticklerish point, but I'm just thinking out loud here! A slightly narrower path would be okay.

    Would you use a spade to keep the lines straight? Good tip about the string too, b/c I do catch the rake on it every time I use one.

    Gardenlen, I wanted to do it without an enclosure. Yes, it will be work, b/c I have 22 beds. I've seen your website before, the straw bale gardens are very cool!

  • tetrazzini
    Original Author
    11 years ago

    Chas, you say the old double digging method used rounded mounds -- you mean instead of having rounded edges and a flat top? My first gardening book was John Jeavons' book, and I double dug. But it was just too much work for me and I eventually began to feel that less soil disruption was better anyway. (I must say, however, that both ways have turned out great crops.)

    Thanks for the tool input. I'm going to buy a D-handle spade.

  • wayne_5 zone 6a Central Indiana
    11 years ago

    I have unbordered beds. I like mine wider. Mine are about 8 inches raised. I added other material to the original topsoil. I suggest any tilling first. Then the loose dirt can be added to the beds from the paths. You don't need wide paths. If you make narrow beds, you have nearly all edges....another reason I like wider beds. Also you then lose less space to paths. I can run a wheelbarrow down foot wide paths.

    The edges are not difficult. They can taper about 60 degrees and stay put. I don't care for much foot traffic, but do not have a phobia about some walking on.

    I don't use string, but just lay out with a tiller. I wish I had a photo to show what really neat beds look like....no working camera and not many stored photos in this newer computer.

  • scotty66
    11 years ago

    you say, "When they get watered they get smooshed down to path level again"

    how are you watering? sounds like your either flooding or using a sprinkler... I would suggest some sort of drip irrigation to keep the water from eroding your beds.

  • tetrazzini
    Original Author
    11 years ago

    Even rain water tends to level the beds. probably b/c they're a little fluffed up when I first form them, then the water compacts them. They're never more than a couple of inches high. This year I'll make them higher. I water with a hose.

    I have a drip irrigation system, but it didn't work very well for a couple of reasons, so I stopped using it.

    I used to have 12" paths, but the foliage from the beds was always overhanging them, so I widened them.

  • natal
    11 years ago

    I use bricks to outline my beds. That's adequate for keeping the dirt in the beds.

  • chas045
    11 years ago

    Yes, Jeavons book was my intro to double digging. I was lucky that there was a group in Palo Alto CA right next to me that taught all about his ideas and about his mentor's (whose name escapes me now) as well. I also had freinds in Covolo CA where this mentor had his test garden so I got to see double dug gardens up close and personel.

    Jeavons did talk about mounded beds. I was just pointing out that precise shape of the edge was probably not that important in holding the soil. However, if you enjoy the look of the sharp edge not hidden with plants then you may as well measure the angles and press everything in with a hand held piece of plywood.

    I admit that I haven't done double digging since I moved to North Carolina, but I may have to go back to it because the weeds are much more agressive here and the intensive beds might shade some of them out.

  • baseball9
    11 years ago

    >>> I want the beds to actually have 30" of flat growing width. A steep drop off to the path would have more potential to wear down. So if I want to kind of feather it out to a 45* angle, as you said, that would mean the bottom of the bed where it meets the path would be a little wider than the top, so the paths would shrink to less than 18", right? A sticklerish point, but I'm just thinking out loud here! A slightly narrower path would be okay. At my community garden I have a 20 x 20 plot, and I did 30" wide beds with 18" aisles. The sides take up some of that 30". I will take a picture and measure how much the sides take.

  • tetrazzini
    Original Author
    11 years ago

    Thanks Baseball. Had you tried narrower paths before arriving at 18"? They just didn't work for me.

    Chas, I think you're talking about Alan Chadwick. It's great that you got to see his gardens. North Carolina gardening? I visited my cousins there when I was little and remember that the soil was like orange modeling clay! It must be a real challenge to garden there.

  • jolj
    11 years ago

    I still double dig, the first time on new beds.
    I have them with & without wooden, stone sides.
    I agree with wayne & baseball.

  • oliveoyl3
    11 years ago

    You can also fill the paths with irregular shaped arborist wood chips to prevent the slope from sliding. It also helps it maintain moisture. Eventually they are compost, so you rake that back on to the garden mounded beds and replace.

    A mix of whatever we have available has worked -- wood chips, straw, leaves, trimmings, etc. -- sometimes covered with burlap bags or upside down carpet for clean paths.

    When our kids were younger they helped water with hoses, so I put bottomless cans, milk jugs, or 2 liter bottles for them to fill because the loose soil gave way with the force of the hose. Now I use soaker hoses, but now & then we get a leak, so it's nice to have the paths filled, so soil doesn't erode.

  • art_1
    11 years ago

    This one is 4' x 25'

    Last fall:

    Some gypsum and a good soaking about 2 weeks before, then watered the day before tilling

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    Leaves, alfalfa pellets, a little gypsum and dolomitic lime

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    Compost

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    Topped with soil

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    This spring:

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    Horse manure, digging, a little gypsum

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    Cousin Itt (compost)

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    Grass clippings

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    More mixing

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    Alignment

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    Soaker hoses

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    Mulched with straw

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    And plant!

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    Making staples

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    Tools used

    As you can see I opted for the electrical tape method to secure the handle on the rake as the collar is plastic on this particular model.

  • chas045
    11 years ago

    Thank you for finding my brain egganddart49. Yes it was Alan Chadwick. And regarding orange modeling clay in NC; that's a great description. I'm going to steal it. When I first dug into it, I wondered why Carolinians weren't all four feet high with distended bellies. As it turns out, I was wrong. It is hard to work and it does need serious amendment. However, the clay holds water AND nutrients wonderfully for extended periods.

    Layered gardening is very popular here. It might be useful in other areas as well. People just throw decayable junk and compostables on top of the undisturbed soil. A top layer might be cardboard and certainly newspaper. It kills the weeds or grass. I think many plow it in when the ground is soft but perhaps just plant into it. It is often called lazannia gardening. I don't use it so I have forgotten the details.

  • baseball9
    11 years ago

    I measured my setup. I actually was going for 40" beds, not 30". 20" seemed to be the distance I could comfortably reach. In my 20 x 20 plot, I did a 1 foot border all the way around. The beds are 40" with 6" on each side for sloping. The height of the bed is 6" at one end, to 12" at the other end (there is a slight slope). The aisles are supposed to be 18". The bed on the north side is only 24" because I am going to have climbing things that will go on that side (peas, cucumbers) and I don't want to walk behind it. So I have 3 40" beds and one 24" bed.

    In reality, the aisles are between 15 and 18 due to a little bit of erosion but also just variance. The sloped sides are between 5 and 8 inches for the same reasons.

    It seems like a good compromise between access and not taking away too much ground space to paths. I tend to let things overgrow. Last year I had 3 48" beds -- it was difficult to comfortably work on the center of the bed, and the plants became too overgrown.

    At this plot, I am also trying out planting some flowers (petunias and marigolds which can supposedly repel bugs) on the slopes and they seem to be doing fine.

    At home, I have similar beds, and I am trying planting carrots on one of the slopes. Another slope I have fennel, I don't know how that will do on the slant. In general, plants don't care if they are on a slope, unless there roots get exposed or they are shaded too much.

    I have been pleasantly surprised that beds like these have minimal erosion. And if it does happen, the soil goes into the path, so it will get reused eventually.

  • spacetogrow
    11 years ago

    I let fast growing weeds grow along the edges of my frameless raised beds. They hold the soil pretty well. As they become larger and more numerous, I selectively remove the non-edible weeds. Then the edible weeds keep getting pinched back for the cook pot whenever they threaten to blossom or get too big. By mid-summer, there are too many other things to eat, and the weeds start becoming determined to set seed no matter what, so I pull them, but usually the main crops are big enough by then to protect the soil from pounding rain.

    I had to learn the hard way that, if a type of weed gets a large, strong root system, pull it before it gets very old or you will rip a gash in the edge of the raised bed in the process of yanking it out.

    I partially back fill the paths with sand. My paths are all on the same level so, except for seedlings, I water by just letting the hose gently flood all the paths while I do something else. The water will soak into the surrounding soil deep enough to encourage deeper roots, and I avoid overhead watering, so the leaves are not as susceptible to some common foliar diseases.

  • tetrazzini
    Original Author
    11 years ago

    I'll see if I can figure out how to post a picture of what I've been doing. Digging out the paths and getting rid of the rocks and throwing the soil on the beds is a big job. I have 22 beds, 20' long each, and the paths have a lot of rocks. It's hard to say how deep I dug, maybe 8" on average. With that soil added to the beds, they're more than a foot higher than the paths. Maintaining beds that high with no frame is hard. Soil slips down, watering erodes them quickly. I learned that I have to set the strings wider than 30", b/c that 30" space includes the slopes and, in effect, I lose bed width. It's frustrating trying to plant on a 30" scheme when you really only have about 24".

    There's always next year to get it right. That's been my mantra since my first garden thirty years ago.

    Next decision will be what to do with the paths. Use straw? Leaves? In these cases the soil might be improved, although it'll be trampled on. Ground cover that can be walked on? Not clear on the pros and cons.