Building a Square Foot Garden on land that holds water

In our next major step toward self-sufficiency and greater preparedness for tough times, we wanted to have a garden.  Now, mind you, we could have saved ourselves great expense and just tilled up a plot in the yard for a regular row garden.  Except that we do actually want to grow something besides rice.

You see, this yard was engineered some 60 years ago as a kind of overflow for water coming down the neighborhood hill.  Why, I have no idea.  It would seem to make sense that you channel the water toward the street, and then into the big drainage ditch behind the neighborhood.  Of course, that would require that you put the right sized pipes in from the beginning (um… no, they didn’t… they ended up replacing them with larger ones some time ago), but maybe designing the drainage correctly so that somebody doesn’t end up with their yard being used as a detention pond makes too much sense.  Maybe there’s something more to this design that I just don’t know about and understand.  *sigh*

(Oh, and making sure that the big drainage ditch is maintained well enough that it doesn’t have trees growing in it would help.  My grandmother spent many an hour bending the ears of the local officials trying to get them to do their jobs.  Especially since their lack of action periodically flooded people’s homes.  Eventually, they did clean the ditch out, and the larger drainage pipe keeps the bottom of the hill here from flooding as badly as it used to.  But I digress.)

So what happens here when it rains heavily is this:  for a while, all looks normal.  It’s raining, stuff gets wet, water puddles and runs down driveways to the streets, water runs down the streets from the top of the hill to the streets at the bottom of the hill.  It takes a while, though, for the water to collect in the yards at the top of the hill enough for it to start flowing.  You look out of our back window to see wet grass, and you move on.  The water reaches the channel at the side of our yard, and, once it reaches a certain depth, it suddenly breaks through into the back yard.  You pass by the back window again five minutes after you looked before and glance outside, and you now have a lake where the yard once was.

Our last heavy rain was almost two weeks ago.  Yesterday was our first rain at all since that day, and it barely rained enough to get everything damp.  Yet the yard has just dried out to the point at which you no longer sink into it as you walk.

So now you have a clear idea of the challenge of having a garden in our yard.  Well, unless, like I said before, we want to grow rice.  I have no doubt that rice would do very well here.

Not to be deterred from self-sufficiency (and fresh veggies), I began looking into how to have a garden in an area that holds water.  The key to it, apparently, is to build a raised bed that is 18-24″ in depth.  Wow, that’s big.  And… *sigh* it’s expensive.

One of the highest points of the yard is right beside a fig tree.  My uncle had built a grape arbor there some 20 years ago.  It was roughly 4′ x 19′, and the grapevines had not survived but a few years (maybe because they still got too much water — it is one of the highest points, but it still floods).  So Shay decided to turn the structure into a raised bed for me.

I looked at different methods of raised bed gardening, and settled on Square Foot Gardening.  I got the new book, which is updated and easier than the original method that the author developed some 35 years ago.  I have read that not all of the plant information in the new book is as accurate, though, as one would like, so it is recommended that it be paired with a book like the Garden Primer, which I already have, thanks to my mom and my uncle.

This method has many great reviews.  People can’t seem to glow about it enough.  There is the occasional person who tries it and doesn’t care for it, but the vast majority love it.

Unfortunately, I can’t build the 6″ deep raised bed that the method calls for.  Mine has to be 18-24″ deep.  So mine will cost significantly more.  But we’ve been selling stuff on eBay, and pooling unexpected checks and such, to build up enough money to do it.

So we went and bought the lumber, screws, twine, and other supplies for the garden.  Shay handpicked every piece of wood for it.

Our nice, fresh-cut-wood-smelling pile of lumber. The box held parts for the wheelbarrow we bought that day as well. Boy, is that thing going to get used!

I know about the debate about treated lumber for vegetable gardens.  That was because of the arsenic compound that was used to preserve the wood.  They don’t use it any more.  The new copper azole preservative is supposed to be safer.  Still, many home vegetable gardens have been built with lumber treated with the arsenic compound, with no ill effects.  It’s my understanding that it doesn’t leach out very fast or very far, and, just because it is in the soil, that doesn’t mean it will end up in your bell pepper.

When Shay took another look at the grape arbor, and found out how old it was, he decided it would be better to replace it than to use it and have to start replacing parts of it in a few years.  So we tore it all down.  Shay figured since we weren’t using the original structure, he could make the garden to the largest dimensions allowed by the wood he had bought.  This turned out to be 5′ x 20′.  The author of Square Foot Gardening suggests that it really shouldn’t be more than 4′ wide (for the sake of easy access), but it isn’t that hard to reach in 2 1/2 feet rather than 2 feet. Adding one foot to the width and one foot to the length adds 24 square feet to the garden, while using an additional 16 linear feet of wood (one foot per side, four planks deep) — wood we already had; we would just be cutting it longer.  Adding 24 square feet to the garden without making it one foot wider would have taken an additional 48 linear feet of wood (six feet on two sides, four planks deep) — wood we would have to buy if we wanted that space.  That was pretty hard to argue with.

Anyway, then it was time to lay out the garden.  With Shay’s construction experience, he was able to get it square and level, in spite of the fact that the ground is quite uneven.

Four lengths of hot pink twine marked out the plot. The holes you see already dug are four of the six holes that held the posts for the grape arbor.

Getting it all level. Shay didn't go for absolute perfection, since this was a garden, not a shed or something. But he came as close as he could without sacrificing a lot more time.

We used old arrows that had been given to Shay as stakes. They were bent or missing fletchings. They turned out to be perfect for use in the wet clay dirt -- they would stand straight unless the twine was disturbed. Instead of being pulled over like a wood stake, they would bend, and then stand back up once the pressure was back off of the string. Yet they could stand up straight under enough pressure to keep the string taut. Shay put a small piece of Duck tape on the arrow to keep the twine from going out of level.

Getting it square. This appears to be out of square, because the long side of the square is running downslope, while the twine is level. If you look straight down on it, though, you could see that it is indeed square.

Then it was time to erect the posts. Unlike the arbor, which had less structure, the garden would not need cement. The rest of the structure will keep the posts in line. As Shay cut wood and we began attaching cross pieces, Mom and I also furiously began emptying old flower pots into the old grape arbor holes. We eventually had to raid my uncle's pile of dirt to finish off the holes, but he still has enough to fill the other yard holes we have.

The top is finished, and the first set of 2" x 6" lumber has been attached. The height of the garden is not necessary or even suggested in the Square Foot Gardening book. It is a mirror of the arbor, and will support more climbing plants for us, and will also support clear plastic sheeting in the winter (we could use hoops, but this should be easier for my mom), as well as netting in the summer. We have incredibly determined birds around here. It also will support hanging baskets, which hoops would not. You can see we finally got all the holes filled in! Shay realized around this point that he had made a mistake in measuring. Forgetting to take into account the thickness of the wood for the sides, the resulting garden space will actually be 4' 9", rather than an even 5'. He said it helps keep him humble when realizes he's made a mistake like that. It really won't affect the garden much, though. I love my Shay!

The three full 2" x 6" layers are in. Additional 2x6s were added inside to take care of the quite variable distance from the ground to the bottom of the first level of 2x6s. The depth of the garden ranges from 19" to nearly 24", because of the lay of the land.

A closeup of the inside. You can see how the bottom 2x6 is angled to meet the ground. The one at the opposite end is actually a 2x4, because it was so close to the ground at that point. Shay initially wanted to dig channels for the bottom layer so that it would be level with the rest, but that would have taken a lot of time and effort, and gained only a little in the way of aesthetics.

The full length of the garden. You can see how the bottom layer is inset, like a kitchen cabinet. This tends to hide the fact that those pieces are angled rather than straight, like the three upper courses are. I think it looks just fine!

Short one length of 2x4, Shay reused a piece of the old arbor as the center crosspiece.

Meanwhile, Bunny-Wan Kenobi used my uncle's dirt pile as a place to try out his John Deere tractor with plow attachment. The little booger really works, too... miniature furrows! Pretty funny. Oh, and that is a medical bracelet he is wearing.

Now that most of the building is finished, we can start filling it.  We’ll put down newspaper first, then chicken wire (for moles), then line pretty much the whole thing with landscape fabric both to keep the mix in, and to keep weeds out.  I then need to put at least six inches of sand in it, to allow ample drainage for the garden.  Excess water needs to be able to drain out, something that would most certainly not happen otherwise.  The rest I will fill with a concoction known as “Mel’s mix” — a 1:1:1 mixture of compost, coarse vermiculite, and peat.  I may go deeper on the sand, depending on the prices of everything involved.  For now, it appears I will need approximately 2 cubic yards each of the sand and the three ingredients of Mel’s mix.  Cha-ching! Now I get to start calling around…


Comments

Building a Square Foot Garden on land that holds water — 12 Comments

  1. on a positive note…you have rabbits! Throw ALL their waste in there seriously. Top Two-three INCHES of dirt. The rest poop. :) and well the bottom few inches with sand/gravel for drainage. But I wouldn’t worry about doing landscape cloth…the chances of weeds coming up through two feet of dirt that you can’t manage is slim unless you have nasty weed/tree growing in your backyard.

    • Oh, believe me, there will be plenty of rabbit poop in there. :D Most of it right now will be composted, because it has so much hay in it. I’ll be working on hay racks soon, which will make more of the bunny berries available to go straight into the garden.

      I do need the landscape cloth… we have vines that are growing through the ground and popping up everywhere in the yard. I’d be shocked if 6-9 inches of sand and a foot and a half of peat moss, compost, and vermiculite stopped those frightful things! We’ve got a long fight ahead to rid ourselves of these vines. :(

  2. Nifty looking.

    I got lucky here, the water table raises to about 6 inches below the surface all winter here, and after growing up on clay soil I thought that would be a nightmare. But the soil here is sandy loam–real flood plain stuff. Drains out in a single day.

    My trouble is keeping it watered in the summer, I used to use soaker hoses to great effect when I had clay, but here it just goes straight down, lol–mulch to the rescue! A raised bed, especially with a sand base, will need more water than you are used to needing…something to watch for.

    • This is true, and it is going to take some real watching. I understand the vermiculite is supposed to hold an impressive amount of water, and the peat moss will as well (as I’ve already seen). But we are definitely going to have to watch it, especially when it gets really hot.

      It is really clay here. I’ve never seen soil that acted like Play-Doh when wet, like this does. And then when it dries, it’s rock hard! In Florida, we had very sandy clay. It was hard to grow stuff in that, too, because it was too sandy.

      I have thought that I might need mulch. I’m hoping not, but I probably will.

      I was starting to wonder if anybody really actually had good soil, after all the bad soil I’ve seen! Sounds like you’ve got it! :D As long as you can keep water in it, anyway.

  3. Sadly I was not born with a green thumb. I’m working on it though. Gardening is a good escape from the world of internet marketing consulting. Good to unplug.

  4. I found square foot gardening a great way to keep the weeds down to a minimum. And lets face it picking weeds is the task that we all dislike the most about having a garden. Great post, very informative

    • I heartily agree! While we’ve had some weeds, they are easy to spot, and easy to pull. They are also not very numerous at all.

      I’m getting ready to plant for fall and winter. :)

  5. Square foot gardening is a situation when you plant and grow crops in an enclosed and raised up bed. It is also known as intensive gardening. You plant and grow plants and vegetables in squares which can vary in size but they are normally 1 square foot each. It is a combination of organic gardening which is mainly focused on compost, close planting or closely raised and planted beds and bio intensive farming or gardening in a clearly marked and demarcated area. This type of farming or gardening is very good and well suited for people with disabilities, beginning gardeners, and places which have a very poor soil fertility and soil composition.

    • It is a method of intensive gardening, and there are methods which are even more intensive than this.

      One reason square foot gardening is very good for people with disabilities is that it can be built in a table top setup, elevating it so that it can be reached from a chair or wheelchair.

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