Introduction: No Irrigation Raised Bed Gardening System (Hugelkultur)

About: I am a web developer with an interest in self sufficiency and permaculture

Approximate Project Cost can be anywhere from free to $100 per bed. Here is a detailed cost breakdown based on Lowes pricing in 16066 and bolts from Tractor Supply (by weight) http://bit.ly/H8tdh5

UPDATE (2014) -

Note: the above pricing is based on my original design. You can save a TON of money by using 2x3 studs and painting them. You can save even more by using reclaimed lumber for free from craigslist.

You can save signifcant amounts of money using a "bagster" disposable dumpster available at Lowes or Home Depot for $30.

After you nail the bagster garden to your frame take a box cutter or other sharp knife and cut the bottom out of it so that it has direct contact with the ground. (outlined in the bagster step)


My garden beds are a combination of a few things I like.

1- would be raised bed gardening and in particular square foot gardening
2- Hugelkultur - this is a technique where wood is buried inside of the garden bed which greatly reduces and even can eliminate the need for irrigation. Don't take my word for it... read this, and listen to this and this For the purposes of this instruct-able I'll ask you to suspend your disbelief and lets just assume your on board with hugelkultur. If you want to debate it take it up with Paul or Jack.

Update (2014) - I never water these gardens and tomatoes and peppers and everything else grows just fine.

Tools I used
Hammer
Pipe clamps (not 100% required)
Circular Saw
Miter Saw (can use circular saw for all cuts, but it makes it easier)
Drill
Tape Measure
Carpenter's Pencil or Sharpie
Level
Mattock (not required but suggested)
Shovel
Kreg Jig - I used the Jr. version
Socket Wrench

Update (2014)
I owned a Kreg Jig so that is what i used. If you do not want to buy a jig simply use 3" deck screws. Be sure to pre-drill each and every hole to prevent the wood from splitting.

Materials
3" 5/26 galvanized lag bolts Quantity: 12
5/16 lock washers Quantity: 12

Plastic cap roofing nails: 50 to 100

Plastic cap roofing nails work best for Ondura or the
bagster garden.

If using galvanized roofing please let me know what fastener you used in the comments.:

Materials to cover your garden with:

Idea #1

Ondura Corrugated Roofing Sheet ** Quantity: 2

Idea #2

Galvanized roofing. The Ondura is on it's 3rd season and still working, but it is showing signs of wear. I suspect metal roofing would be more durable

Idea #3

Break down pallets to sheet the frame. I would put the frame in it's final destination first. I would line the inside with plastic sheeting or tarp first before filling which will make it last a lot longer. Used plastic cap roofing nails.

Idea #4

Reclaimed materials from the local dump or craigslist. Any type of plastic or metal sheets, plywood etc. If you are using wood I would coat the inside with tarp or plastic and paint the outside with exterior grade paint.

Structure

Idea #1
Pressure Treated 8' 2x4 lumber* Quantity: 9 Update (2014) - Add 2 additional (approximately) 2x4s

Paint the outside of the beds after they are installed.

Idea #2 Reclaimed wood from craigslist or construction projects. This is what i used for my bagster garden. I stained them with a fence stain after they were assembled. I manually removed all the nails with a simple hammer.
If you want to save some time you can buzz everything off with an angle grinder.

Idea #3 Untreated 2x3 studs. These are $1.80 each. If you are using the bagster garden I think these would be ideal. For best results paint or stain the frame prior to installation of the bagster garden. This would bring down the price of the garden to a significant degree.

Screws:

2.5" Kreg Screws Quantity: 56

Update: If not using the kreg jig get 3" deck screws and make sure you have a drill bit to predrill all the holes.

Note: I would suggest getting your bolts at a place that sells them by weight such as tractor supply. It will end up being a lot cheaper.

Cut List for 2x4s (or 2x3s)
8' (note does not require cut) Quantity: 4
4' Quantity: 4
17.5" Quantity: 14 Update (2014) - +8 additional supports.

* My research indicates that current, modern, pressure treated lumber is safe for use in the garden. Please do your own research and present facts rather than flames should you choose to comment on this material. A more expensive alternative would be cedar or redwood.

Please before you spout off about "arsenic" in the comments be aware that ACQ treated lumber does not contain this substance!

http://www.walterreeves.com/uploads/pdf/acqwood.pdf

**Ondura is light, easy to work with and cheap. However if you are uncomfortable with plastic in your garden you can use traditional metal roofing for this project

Step 1: Step: 1 - Cut All 2x4s to Length

I suggest using a miter saw if you own one, however a circular saw is fine or even a manual cross cut saw will get the job done. Cut all the 2x4s and make a stack of each type by cut

Cut List for 2x4s
8' (note does not require cut) Quantity: 4
4' Quantity: 4
17.5" Quantity: 14 (update (2014) + 8 additional)

Step 2: Kreg Jig Step: Drill Your Pocket Holes

If not using a kreg jig please proceed to next step

Drill all of your pocket holes.

You will need 10 pocket holes (5 sets of 2) in each 8' board
You will need 4 pocket holes (2 sets of 2) in each 4' board

Update (2014) - I would add a minimum of 2 additional 17.5" supports to each side (total of 8 supports). Just evenly space them.

First mark your boards where the edges of your 17.5" supports will be with a pencil or sharpie. Refer to the photo for the approximate dimensions. You don't need CNC machine precision here. Just make the middle support centered and the other 2 supports should have a 10 3/4" gap from the edge.

The 10 3/4" gap is significant. The ondura sheets are shy of 8' long so one of these supports will cover your overlap and hide the seem. The one on the other side exists for symmetry in addition to support.

The Kreg Jr. Jig comes with an instruction manual which should be adequate, however watching this video should give you an idea of what is involved:

Step 3: 3" Deck Screw Step

If using a kreg jig skip this step.

Use the spacing from the previous step for stud placement. Note that the new design calls for 2 additional supports per side. Just evenly space them.

Predrill each hole to prevent splitting. Simply drive the screws in from above

Step 4: Screw Your Panels Together

Lay your 2x4s out on a level surface.

If your 2x4s are bowed you can clamp them using some long clamps such as pipe clamps to hold them in position.

Drive your 2.5" kreg screws into the 17.5" supports.

You should now have finished panels ready to accept Ondura sheeting.

Update (2014)

Use a bagster dumpster or galvanized roofing panels.
The Ondura works, but requires more bracing than the original plan allowed for for sure.

Please bear in mind that the side with the exposed pocket holes should face inward (so that the joints are hidden)

Step 5: Ondura Step: Cut the Ondura Roofing

If you are using a bagster dumpster skip this step

Cutting ondura is easy enough with a circular saw and a rough measurement. Make sure the hump faces up when you are ripping it. Refer to the first drawing

To do your cross-cuts you will have to readjust your blade height.

I would advise you to cut it outside on some saw horses. Adjust your circular saw to the minimum depth required. There is no need to make sure the cut is perfectly square as the edges are not going to be exposed in the final product. Just eyeball it.

Step 1:
-----------------------------

Rip both sheets lengthwise at 24"

You should now have 4 approximately 7' long sheets of ondura.

You want to leave a minimum of 2.5" of exposure on the end of each panel. Refer to the second drawing

Step 2:
Measure your 4x3 panel 2.5" in from both sides. Cut 2 pieces to fit this width

Step 3:
Cut one of your scrap pieces in half. You will use one these to fill the gap on the end of each of your 8' sides.

Step 6: Ondura Step: Nail Roofing Material to Panels

Note: If you are using a bagster dumpster skip this step

On a flat surface face your pocket holes up. Lay your roofing material down on the frames. If your edges overhang make sure that they only overhang on one side. This can be the side that rests in the soil. You do not want exposed roofing edges.

Drive galvanized roofing nails liberally to secure the roofing material to the frames.

Update: Make sure to use the roofing nails that have the plastic caps! (see the photo I added)

A finished 2x4 frame should look like the one in the first photo. I don't think it matters which side you face out. I chose to face the black side out, however ondura comes in a variety of colors and you might wish to face the color side out.

I had roofing nails left over from another project and used both the standard nails and the ones with the plastic caps. I found the plastic cap nails to conform nicely to the curves of the ondura. Overall I liked using those better than the standard ones.

The second photo illustrates a completed bed.. you can see the roofing nails in it. I tried to space them fairly evenly.

Step 7: Bolt Together Your Panels Into the Final Bed Shape

You should do this on a flat, level surface such as a driveway, deck, or patio.

Hold one side up to another. It helps to have a partner hold them together or in my case I used some quick clamps as an extra set of hands.

Pre-drill a lag screw hole in the top 2x4 and drive in a 3" lag screw with your socket wrench. Make sure the tops are flush before drilling!
Drill a second hole in the middle (eyeball it) and drive a 3" lag screw there
Finally drill a hole in the bottom and drive a 3" lag screw there

You will be using a total of 12 3" lag screws to bolt all 4 frames together. There should be 6 bolts on each side

The photo shows what it should look like

These are pretty heavy, so assemble this as close to where it will go as possible.

Step 8: Bagster Dumpster Step

After you bolt your raised bed together you can put your bagster garden in it.

  • Using plastic cap nails work your way around the top of the bagster dumpster. Put a nail in every 6 or so inches (use your best judgement)
  • Next work your way down the corners with plastic cap nails.
  • Once you have fastened the corners and the top you can add a few additional into the supports if you want on the sides.
  • At this point get a box cutter or other sharp knife and carefully cut the middle of the bottom of the bagster garden out. I left 8 to 10" around the edge. I felt this would better contain the garden while providing drainage.
  • Cut the handles off if you want to... i didn't bother.

Step 9: Level the Bed

Ok now you can stick this out in your lawn or garden spot, wherever that might be. Your putting logs and 2' of soil in there so I'm not concerned with putting down cardboard first, however that is up to you.

Take your level and place it on the bed.  Dig a trench with a mattock and scoop it out with a shovel around all sides until you have made the bed level. You can dump the removed soil into the middle of the bed. I chose to reserve the soil and dump it on top of the logs after I did step 8.

The photo shows 2 leveled beds

You can see the trench required. These were placed on a slight slope and one end needed to be dropped about 5"

Step 10: Pallet Wood or Reclaimed Wood Step

After assembling, placing your garden to it's final position and leveling it you are ready to sheet it with reclaimed wood or pallet wood.
I would recommend first painting it with an exterior grade paint.

After you have painted it then cover it with a vapor barrier such as a plastic drop cloth or cheap tarps from harbor freight.

Attach these using plastic cap nails. Paint the entire garden frame for best results.

Step 11: Fill With Wood

Fill your beds about 1/2 way or more with a variety of woods. I used maple logs and apple/pear wood since that was what i had available on my property. You need to leave between 6 to 12 inches for root growth.

I first layered the bottom with the largest logs, second I placed much smaller branches all around.

If you have leaves you can put down a thick layer of leaves here. You can also scoop in any excess dirt from leveling the beds on top at this point if it was left around the edges.

If you want an even greater effect you can dig out the bottom of the bed to make room for more wood, that's up to you and how ambitious you want to get.

The photo shows my beds awaiting soil.

Step 12: Fill Beds With Compost

Fill with compost. At this point you need to find someone who has a pickup truck/trailer, or have a local landscape place deliver you a load.

We found that 1 pickup truck full (2 "scoops") fills up one bed.

We used a combination of organic cow manure and organic mushroom compost.

In the very top layer I mixed in peat moss and vermiculite to make my "mel's mix"

The attached photo shows the bed before I added the vermiculite and peat

Step 13: Square Foot Gardening Grid

Square foot gardening (SFG) Involves a grid of 1 foot squares where you plant different crops in different squares. This makes it easy to create a polyculture in your garden and to practice effective crop rotation in your garden.  

Here are some links to some free square foot gardening planning tools:
Gardener's Supply
Smart Gardener

In his book "All new square foot gardening" Mel suggests only using rigid grids. I find rigid grids harder to work with and more expensive to install.   I prefer a simple Nylon clothes line available at any home center. I even got a glow in the dark clothes line from Harbor Freight.
  1. Cut a scrap piece of wood to 12" long
  2. Using the wood as a spacer add a galvanized nail every 12". I chose to drive my nails into the side of the bed rather than the top. This is so I can leave the top flat in case I want to add a green house to the top or otherwise utilize that surface area.
  3. Tie the clothes line to a nail and simply start wrapping it around to form the grid. I started in the short dimension first for no particular reason.
  4. When you get to the point where you need to change direction you will need to drive an extra nail in that corner.

It is really very simple, however  please refer to the photos for clarifications.


To come:

1 - removable deer protection panels
2 - pvc trellis
3- SFG grid
4- cucumber trellis
5 - pvc tomato grid