Building gardens in the sand

I’ve always wanted to be a landscape architect. Here is my latest project at a friend’s house two blocks from the Atlantic Ocean. There is a salt marsh across the street.

What I already know how to do is grow midwestern plants in black dirt. Now I am going to try to grow perennials like hosta, iris, and daylily in something like sand.  The plan is to add enough organic material to the soil so perennials will grow.

future  garden sandy soil

Now my shovel has hit something hard at the corner of the building–it’s a huge concrete disk. Usually I would just remove something this size since the plants’ roots can’t get through it, but is this something structural? It looks like it should be under the square cinderblock behind it that the porch rests on, but it’s just loose. Maybe it’s supposed to keep the cinderblock from moving forward? I suppose the thing to do is just leave it covered up the same way as I found it and plant something with shallow roots above it, but it would be nice to know its function. (Click to enlarge)
corner of porch concrete disk by cinderblock holding up porch
Also I am told that the topsoil here just blows away. Not sure how accurate this is. So I guess I have two questions–how to keep the porch from falling down and how to keep the dirt from blowing away.

UPDATE: Here is a “during” and “after” picture. I added about an inch of sphagnum moss and a few bags of topsoil to the top and worked it in with a shovel, then used the rest under the plant roots mixed about 50-50 with the sandy soil already there.

NY and Massachusetts 020 IMG_3818

Another update:

Here is another view of the piece of mystery concrete under the corner of the porch. I’ve changed it to grayscale to try to make it more visible.  The porch itself rests on a square block.  The block looks like it should rest on the round thing, but the round thing is completely loose, although the edge of it is under the block by about an inch.
porch block


13 Responses to “Building gardens in the sand”

  1. A. J. P. Crown Says:

    Plants don’t like salt. One thing you can do is lay a roll of polythene sheeting (like garbage bag material) a foot or so under the surface and fill it up with proper non-salt soil.

    There’s a saying:
    “sand on clay goes away, but
    clay on sand makes land”
    in other words, if you mix a clayey soil into sand it will improve it. Then you need to mix lots of composted material (grass clippings, animal manure (not dog, don’t know why) old plants and clippings) into the soil. Tree branches and stuff that’s been through a wood chipper will make the soil looser & allow air in to it (a good thing). If you don’t have access to that stuff you can get it at garden centers. I’ve found that adding fertilizer in the spring makes things grow a lot faster and bigger — but it’s not so good for the environment.

    It is dangerous to excavate right next to a building’s foundations because there’s nothing to stop everything from sliding outwards. (A six-story building down the street from me in NYC collapsed that way, it was horrible (people killed).) I can’t tell you whether it’s okay to take that block away, but it certainly looks to me like it was put there for a reason, possibly frost-related. If there’s room, you could put your border a little way from the building and have paving or grass (has to be mowed) or pebbles right next to the building. Make sure anything is well below the level of the red-painted wood panelling or that will rot.

    Or you could have tubs instead — wooden barrels are nice, painted white, and stick the perennials in those (put rocks in the bottom for good drainage of the soil). I love geraniums, is that what you’ve got in pots there? They look perfect in tubs, very cottage-y.

    I can’t believe I’m giving gardening advice. Me, the city boy.

  2. Nijma Says:

    Thanks, Kron, I like that saying about sand and clay. Every property I have lived on in Chicago has had a drainage problem because there is a layer of clay about a foot under the topsoil. Typically the clay layer is about a foot thick, so you can get well past it by digging a dry well about ten inches across and three feet deep and filling it with rocks. I can’t tell you how many dry wells I have dug and how much fun it is to see standing water go down the dry well just like water in a bathtub.

    That round piece of concrete is very strange looking to me, but I uncovered another one further down, just the same. The top is flat but the bottom is rounded; the whole thing was tipped, and just the edge was wedged under the concrete block that apparently holds up the porch. If it is meant as a support I don’t think it’s doing a very good job. About six years ago the door wouldn’t lock properly so I moved the strike plate for the bolt and chiseled a new slot for it. Now the mark I made for the center line of the bolt is a half an inch too low. The whole building is tipped somewhat towards the front of the property, but the front porch seems to be tipping separately and at a faster rate.

    I tried to keep most of the soil off of the wood of the building, but there is also a concern about animals getting underneath. Once there was a litter of kittens under another part of the building, but there is also something else that annoys people here, I think maybe some kind of badger.

    Anyhow, the thing is done. The spiky plants are irises, the others are all hostas of different colors and varieties. There are a few red geraniums planted on the sides close to where people walk–the area in front is for parking. The hostas were all divided from plants in Chicago and you can see how wilted they look after 3 days in the car. They have been watered copiously and should perk up again after about 2 weeks.

    • A. J. P. Crown Says:

      Good job, Nij. It looks lovely.

      • Nijma Says:

        I’m glad it’s done–I was afraid the plants would die before I could get them in the ground. But I’m a little bit sad because I think we just broke up–as much as you can break up with someone you see less than once a year.

  3. Siganus Sutor Says:

    Plants don’t like salt.

    Goat’s foot don’t seem to mind.

    is this something structural?

    Even if they often tell a lot of bullshit, maybe you could ask a structural engineer?

    • Nijma Says:

      I thought about asking you, Sig, but had to do something with it quickly. Do you have an idea about it? I will probably never be there again, but I still think it’s interesting.

  4. Siganus Sutor Says:

    Incidentally, Nijma, your third photograph completly wrecks the shovel theory I developped over the years. I managed to reach the conclusion that the world was divided between French-like-shovel territories and English-like-shovel lands. From say Inverness to Cape Town you would have English-like shovels with a shorter shaft and a transverse handle and from say Calais to Agadir you would have shovels with a longer plain shaft with no transverse handle. Now I see that against this Californian red wall you have both types of shovels. What am I supposed to do now that one’s lifetime work has been reduced to dust? Dig my own grave?

    • Nijma Says:

      The long shovel is the standard here, but I am international.

      I use the large one for digging holes, turning soil, and dividing hostas (my mother got it for me). The shorter one I got at a garage sale and I use it for transplanting. Most people here use a small trowel, but this one is easier on the back and knees.

  5. Siganusk Says:

    The long shovel is the standard here

    So the U.S. are in the French part of the world? Fascinating.

    Incidentally, accidentally, I have posted another comment here that got stuck into “moderation”. It seems that it has disappeared now. In your dust bin maybe?

    • Nijma Says:

      I have found the comment and set it free. A while back some people were writing a lot of profanity while I was at work, so I put in a filter for bad words.

    • Nijma Says:

      We drive on the right side of the road, too.

      • Siganusk Says:

        On the wrong one you mean, don’t you?

        Is the house a prefab one? It could have been the concrete pieces on which the construction was set out. But it looks a bit thin and small to be the actual foundations. If they came out easily they couldn’t be the foundations, and it shouldn’t be much of a problem to remove them (unless they were there to hold some services like waste pipe?).

      • Nijma Says:

        The owner could tell me nothing about the construction of the house. Apparently the previous owner was absolutely certain the concrete slab that looks like a piece of sidewalk was probably holding the house up and should stay where it is forever. You can see a notch cut into the building to make space for it. This concrete slab will eventually be nearly covered by plants with very large leaves.

        It’s definitely not for services since both water and sewer are on the other side. They always freeze in the winter, too. A lot of the houses there have that problem.

        I heard that a lot of buildings around there are built on poles that are driven into the sand. The floor of this particular building slopes visibly down towards the front, and the porch slopes too. It has moved about a half inch in the last 3 or 4 years since I chiseled a new hole for the lock bolt. That makes me think there is something wrong with the foundation under it, since it is not stable.

        I have found another picture of the corner–maybe this one is more clear. If it was my building I would probably wedge that round thing under the block and see if I could get the corner to stop sinking. But it’s not my building and the owner wanted it left as is. Oh, well.

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