Introduction: Double Decker Greenhouse Garden
Great garden in a small space for a short season.
Recycle an old swing set into a green house. Put a shelf across the middle of the swing set to add garden space, or simply hang upside down pots or planters from the existing swing set hooks. Add a climbing wire for beans. Then, set up your watering system, plant, cover with plastic and watch your garden grow. This double decker greenhouse is sure to add a couple of weeks growing time on each end of the growing season. That's a precious month for a zone 4 gardner.
Step 1: Prepare the Plot
My awesome Mother help me dig down 8 to 10" with a pick and shovel and then removed half of loosened hard sand and clay. Next, we mixed in some really excellent dirt from a worm farmer which was one-third worm castings, one-third manure and one-third top soil. I paid $40 for 1.5 yards; this project took 1 yard. The worm farmer said more than one-third worm castings will produce great foliage but no flowers. This is a picture of my Mother and the Earth Angels blessing my new garden spot.
The swing set I salvaged from a metal pile at the dump had a foot print of 5.5' x 10.5', plus we added an extra 4' of garden to one end, since I had the space.
Step 2: Greenhouse Frame in a Flash
Simply haul in the swing set dump find and set it in place over the garden plot. Remove any swing set hardware that crests the top bar and may tear the green house plastic. I removed the swing set glider hardware shown with vise grips rather than take time to find the right allen wrench. You will want to leave the swing hooks on the top bar for suspending potted plants or climbing wires.
Next, decide whether to hanging potted plants or add a shelf. Since I was lacking upsidedown pots or hanging pots, I went with the shelf.
Step 3: Shelf Space
For the shelf, measure the distance between the two horizontal cross members (10') and add about 6". I went with two recycled gutters and one old board to set potted plants on. So far, I'm pleased with the gutters, they are just the right height to plant in and snip a bit of lettuce for lunch. The gutters are too flexible by themselves to support a load of wet dirt, so I added some rope suspenders to the swing set hooks or over the top bar. I recycled some green baling twine for this job. I tried to tie the gutters high in the middle so the gutters would flex down towards the ends allowing water to drain from the ends. The old board is for setting recycled food containers on which will be used as planters, you'll see that in a later image.
Step 4: Gutter Fill
I wanted the gutter to drain in the event of too much water. So, I added gravel to the bottom, then some rabbit manure for fertilizer and filled with soil. The ends are duct taped to prevent soil loss but have a small opening near the bottom for water seepage.
Step 5: The Bean Trellis
While I was looking for the baling twine, I found a scrap piece of sheep fence. I turned it sideways and inserted it vertically adjacent the gutters for a bean trellis. Strings extending from the top bar and staked to the ground would work just as well. Later, I planted beans near each of the swing set legs to let them climb the swing set frame.
Step 6: Watering System
My ideal garden has an automatic watering system so I can go camping for a few days. I'm not at my ideal system yet. One idea, is a PVC pipe with three misters suspended from the top bar, and a drip system on the ground, all set to an automatic timer.
For now, I salvaged a piece of drip line for the ground. The black pipe drip line has drip ports every foot and a half. For watering the shelf layer, I added a pipe 'T' between the garden hose and the drip line. The pipe 'T' is connected to a valve and a length of salvaged washing machine hose. The washing machine hose is connected to an adjustable sprayer which is shown removably wedged between the two gutters. Since the sprayer is adjustable, I didn't really need the valve. The washing machine hose has two female ends so I needed a 3/4" male-male pipe connection. At the spigot, I added a timer but this timer requires daily setting and is more for preventing forgetting to shut the water off.
As you'll notice there is standing water in the gutter, this is from a failed attempt to suspend an old shower head from the top bar. The flow was not quite right for the application and the hose connections were a bit of a pain, but old shower heads may have a purpose in gardening.
Step 7: Plant & Cover
Now the fun part, plant and cover! The plastic is a rectangular piece. Mine is extra big since it's salvaged from a commercial greenhouse and I'm going to use it later for a painting drop cloth. It's not pretty but serves it's purpose of preventing frost and warming the soil. The extra length is useful to cover the four extra feet of garden space beyond the end of the swing set.
To determine the plastic size, first measure the swing set height (6'), the length of the top bar (9.5'), and one diagonal leg (6.5') from the top to the ground. The short direction is 2 times the diagonal leg plus two feet (2x6.5+2=15'). The long direction is 2 times the height plus the length of the top bar, plus two feet (2x6+9.5+2=23.5'). The two extra feet allows one foot all the way around to anchor the plastic to the ground.
I folded one end in like wrapping a present and the other end I extended over the extra garden space. I used a few heavy rocks for anchors. Stakes may be better in windy locations. Guy wires from the top bar down to the ground underneath the plastic may be useful for preventing the plastic from drawing inward on the sides. So far, my rocks are working fine for this too. We had some 35 mph winds at the green house is still standing.
In an alternate attempt I tried to wrap the swing set frame from the bottom up with clear plastic pallet wrap, but it tore as I started and I gave up early. Clear plastic pallet wrap probably has a gardening use, but for this project the free plastic was too easy to refuse.
That's it, easy peasy! Free from salvaged goodies with the exception of the dirt and I'd rather buy good dirt than gold anyday. *** Happy Gardening! ***