Advice sought about Food Forest/Swale for sloping plot

Discussion in 'Planting, growing, nurturing Plants' started by TrevNorman, Sep 28, 2011.

  1. TrevNorman

    TrevNorman Junior Member

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    Hi all, great place to find out lots of info, thanks. I hope someone might be able to help me with a question on swales (as the start of a Food Forest)

    I have a plot set aside of about 2000m2 however the slop is from one corner to the opposite corner. I don't have a straight line to put a swale on as the straight line would be heading downslope (and I believe that swales should stay on the same contour?) Should I build a small swale that curves around the top corner (like a quarter of a circle, forming a pie piece) and then build further swales outside that, in increasing arc lengths but parallel. Or go with the long straight swale that runs slightly downhill (1/2m drop over 25m).

    Thank you for any advice.

    Trev
     

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  2. Grahame

    Grahame Senior Member

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    HI Trev, you need to keep it on contour, otherwise the water will all just drain down to the downslope end of the swale. You don't need a straight line - nature hardly ever works in straight lines.

    What do the properties to either side of your corner look like - i.e will you be collecting the water running off of those two properties as well?
     
  3. Raymondo

    Raymondo Junior Member

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    You could make a cheap water level to help set the swale lines on contour. Plenty of info on the internet on how to do this. You need two people when marking out though. A smaller, one person contour marker is an A-frame with plumbob. You also need to think about what will happen to overflow water. I have two swales in my yard, also about 2000 m2. The swale ends are slightly turned 'upwards' (think Mona Lisa smile) so that overflow is over the top of the swale though in 3 years it hasn't rained enough to actually test the overflow.
     
  4. S.O.P

    S.O.P Moderator

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    Or, conversely, your swales on contour when overflowing can fill the one below it. Like a tower of champagne glasses, if you can visualise that.

    Or, if that's too hard, you can do the 'boomerang swale' thing, and stagger offset them across your fall.
     
  5. TrevNorman

    TrevNorman Junior Member

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    Thank you everyone, I will build the swales along the natural lines, this seems the best way to make use of their water collecting purpose. I think the "old" gardener in me wanted neat, straight lines, but that will not be the case.
    Thanks again for the help.
     
  6. annette

    annette Junior Member

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    I hope you don't mind me tagging on to this Trev, but I have an area very similar to yours that I am designing for a garden too. However I have clay soil with gravel on top and so want to build up the gardens. So I don't want to dig and the grounds too hard anyway. I was going to lay out tree logs in the quarter circle pattern in a sort of terrace pattern down the slope on contour. I'm hoping that will catch the water rather than escavating. Does anyone think this will work? Next door has water come down from the left hand side.
     
  7. pebble

    pebble Junior Member

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    Location:
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    Climate:
    Inland maritime/hot/dry/frosty
    You could do hugelculture!
     
  8. annette

    annette Junior Member

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    Hi Pebble, yes I think I will do it hugelculture style. There's lots of info on it. Sepp says to make the piles about 5 ft high and others not so much. Some say plant straight away and others say let it sit for a while. I suppose it is a bit of trial and error and see how things go. So I will start with a garden down the bottom of the slope so it gets lots of water and then gradually work up the slope with others as the wood becomes available. I have many cut cocos palms and a few other non-native trees I have cut up. Also some old banana trees cut down and lots of twigs and leaves so should be able to get a garden of about 3m x 5m x about 3 or 4 feet in height. I'm thinking it might deter the bush turkeys a bit (want to learn about perserverance, watch a bush turkey) without me having to put a big fence around everything. I'm going to put some smaller branches around it all so they can't scratch around too much. That's the plan anyway.
     
  9. Raymondo

    Raymondo Junior Member

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    If it were me annette, I'd be working from the top of the slope down. My place is clay and the water runs down in sheets when we get torrential summer rains. Starting at the bottom could be problematic as the garden/swale would bear the brunt of the collected runoff. By starting at the top the risk of it being overwhelmed is considerably reduced. Alternatively, plant on contour higher up the slope. Something like lomandra would work well I think. Just a thought.
     
  10. S.O.P

    S.O.P Moderator

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    I just built one in the park opposite (or near to be exact) my house in Kurwongbah Park, not too far from you.

    Tear drop shaped, logs held up with a small amount of dirt on either side and completely mulched (just mulch would of been fine but I'm looking at public safety). Waiting for it to catch water and hope my levels are right, since I did it by eye and wasn't too concerned about the final result since it's not my house. I will be planting A. fimbriata, A. melanoxylon, Lomandra longifolia and hystrix on the wet side, Dianellas and a 300mm Ficus macrophylla I have at my home, plus whatever other natives I can get my hands on. This is in park-mown dry sclerophyll, zero organic matter and compacted clay. There was a minor depression there that I identified as a planting spot 2 years ago but whatever I planted was vandalised immediately. The acacias will be my sacrificial lambs, this time.

    Feel free to drive past and fiddle with it. I'm not a Master of the Subject, but it may give you some sort of idea.
     
  11. annette

    annette Junior Member

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    Raymondo good point. I will start up the top first.

    SOP I will go and have a look today at the Park and see your work. Do you know about Kumbarcho Sanctuary at Eatons Hill? You can get natives specifically from this area there for $1.50 each.
     
  12. S.O.P

    S.O.P Moderator

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    I use the Petrie Council Nursery. The guy running it is a professional, plant quality is higher.

    Osmocote in the mix though.

    Recommend you check that out too for plants that are in larger pots (tube, 4, 6, 8).
     
  13. annette

    annette Junior Member

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    Hey SOP, I went and had a look at your project in the park. It looks like it will work, but I'm not an expert either. The slope isn't too great so don't see it washing away or anything. The logs, apart from the ones in the middle are pretty well hidden so no-one should get hurt. It's away from the swings too. the slope on my property varies from about 5% to maybe 15% so I'm thinking the shapes will be different in places. But I'll start up the top and observe and work my way down. I just sat there for a while today and imagined how the slope from the property next door will direct water onto my property. I'll build it up the hugleculture way and probably do the champagne glass type of set up. but will have to build the first one and just see first. I'm in a koala corridor and can't cut down trees (not that I want to) and will have to work around them and observe where the sun is at different times of the day.

    Is that nursery near the roundabout to frenchs forest?
     
  14. S.O.P

    S.O.P Moderator

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    Yes, Woonara Drive, Petrie. MBRC nursery, near the water tower. Bought 12 fimbriata tubes and melanoxolyn 6-inch at lunch. Wed-Fri 1300-1530. And just planted the melanoxylon in that structure you saw on the western side, dry clay and gravel, like your soil.

    I read your PM earlier, you sure excavated swales are off the table, or is it because you are working in and amongst the trees? And I do remember reading gardenlen even advocating straw/hay bales on contour staked in, something else to consider.

    Keep on mind, that Holzer's structures are for warmth as well, hence the height. We aren't short of heat here.
     
  15. annette

    annette Junior Member

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    yes there are too many trees around to excavate. so many ideas to consider!! thanks SOP
     
  16. Pakanohida

    Pakanohida Junior Member

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    That is actually the dangerous way of doing it. You start at the bottom and go upwards for 2 reasons. One, your soil should always go up, not down in order to stop top soil erosion & secondly, if you have a mishap which can happen, you will have nothing below set up to help catch it and you can wind up doing more harm then good. For example, last year someone worked on a terrace over looking a highway near here and last spring it blew out through all the trees below, and across 4 lanes of traffic.

    Read up on it from Sepp Holzer and other people who practice terracing prior to trying it yourself.
     
  17. S.O.P

    S.O.P Moderator

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    Why did the terrace fail?

    Theoretically, if you did it 'right', you could start at the top? As long as overflows and weight concerns were factored in?
     
  18. Pakanohida

    Pakanohida Junior Member

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    How does erosion factor into that? You go bottom up to protect soil first and foremost.
     
  19. annette

    annette Junior Member

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    Well I'll just have to see how it goes now. I built a hugelkultur mound up the top over the weekend. It ended up being about 6 metres long, 2 metres wide and about 1 metre high. The bones are there and I have to cut up twigs, gather leaves, old straw from the chook house and start filling up the holes. I won't have enough stuff so will start at one end and plant out straight away with the soil and compost that I have. Then just fill in as I go. I've set it up so that anyoverflow will go to another area that should hold the water down the slope a bit. Fortunately the guy next door got energex to drop off a whole heap of wood in his yard directly inthe path of the flow that goes into my property. Hoping that will stop a bit of the water.

    Clay and gravel soil, slope, trying to stop water getting in under the house, keeping bush turkeys and possums at bay to some extent, trees and roots and trying to use 'on property stuff' is working the grey matter out a bit. So it's a trial and error sort of experiment, observing and coming up with ways to overcome any challenges that arise. I should go and take some photos.
     
  20. S.O.P

    S.O.P Moderator

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    Knowing and living the area, I could almost guarantee erosion isn't an issue where she is. Our hardpan clay remains unchanged in most areas even after all that flooding, except where you would expect. Most of the 'soil' went years ago, after logging and farming finished up.

    Something to keep in mind though.
     

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