Our discussion today focuses on the ground level up to construct a 10” wide X 20’ long Growhaus © II. The up ground design focuses on strength and inexpensive construction. If you forbear the below ground construction we discussed last week your costs could even be less, plus a lot less work-well it is not that much work, just a few days time, and if this old man can do it, why can’t you?
The framed-in planking is the easiest for me, although the more advanced would probably use cinder block, brick or stone. Once all the layered soil and manures are in place you will see that the level will settle a few inches over the season, and to this you simply add more if you wish. This is a good time to let it set a couple of weeks and let the weeds pop up. You can sterilize the top inch of soil with a propane torch, but I think just scratching the grass roots out would be simple enough and as mentioned cover with a layer of sterilized garden soil. If you do not want to spend the money for a few bags of commercial prepared soil such as the Miracle Grow Organic Garden Soil ©, then you can take about 3 cinder blocks, start a charcoal fire on the ground in a safe location, place a large container (I use a cut in half 55-gallon steel drum), partially fill with soil; and cook it. About 160 (o) F will kill off everything undesired. If you over cook you will kill beneficial life. You can check the temperature with an oven thermometer. Then shovel in and rake it flat.
This will not protect you forever, but for a first season. Weed seeds drift in- eventually there is no hope. However another technique suggested with the Growhaus © I was sowing New Zealand clover which will form a tight mat, providing nitrogen and choking out weeds. With this method you will have to insert pre-started plants of at least 4” to 6” high so they do not become choked out too. This technique is also wonderful for the earthworms that come up at night to garden for you, and a light misting from a hose or can really makes the garden grow. Add a couple of toads too, and a pan of water for the toads to soak in if their skin gets dry. They will reward you with sniping up the moths, but will not have much success with earthworm depopulation.
If you are a direct seeder and or want to start your transplants directly in the soil, or even use flats for carrying to the main summer garden, the clover is out, at least on one side of the two beds.
Direct seeding will be no problem in bare soil as you can mark the plants with a plastic or treated wooden tongue depressor sold in the craft section of your sewing store if Wal*Mart ™ is out of stock. The wooden large sticks are best dipped half way in Copper Brown and dried so that they will not quickly rot off leaving mystery plants for you. Use a big felt tip marker on the untreated end. Wear eye protection and gloves with Copper Brown.
If you are starting your seeding early in the spring-late winter stage it gets cold in the Growhaus © II, as it does in any hoop type non-Solar design. You can compensate by buying an underground heating cable and following directions for installation below the soil level you will have a steady flow of heat. The commercial grade cables are the best, albeit costly, but they seemingly last forever and our northern readers will be grateful.
Additionally you can make the Growhaus © II hold more heat and keep out the cold by making a mini-hoop covering of ½” plastic PVC pipes and trapping the heat from the soil and soil cables. While we are at it, when we get ready to cover the entire Growhaus© II we can take an additional same size clear covering and install it with the clamps and tape on the inside of the structure, then place the same size plastic sheet over the outside. This gives you an air gap and adds to the R-value of insulation. I would suspect this could provide reasonable protection down to zero F. But you have to have sunshine; that is the source of heating.
One of the concerns in any “greenhouse structure” is too much heat in the summer. I notice that the manufacturers are now offering more and more vents and of course fans. Since I have elected the 2’ wide, hip deep walk way and the centerline height above the beds is 6’, the amount of heat trapped in the summer time and pushing itself downward is not a big deal-but who knows? This next sun cycle could produce severe summer heat and of course our southern readers will normally wilt unless they have ventilation. The only way to avoid too much heat is to have a high roof center, yet if you get too high you cannot heat trap in the cold winter nights.
My compromise is a simple roof wind turbine, costing under twenty dollars (US). This is affixed on a 2”X4”X10’ treated and painted white structure centerline. The inside view of the lead-in picture shows that on each side of the walkway there is a frame which supports the ribs and the turbine. In the winter time the turbine is simply plugged from underneath with a plastic bag full of shredded paper. The door is left open but I would recommend making a simple screen door on opposite hinges, or to set in place, to keep the undesirable cabbage moths out and etc.
We mentioned that around the top boarder edge of the base are 1” x 6” treated boards that we will use to tack the plastic clear cover down. This board also supports the frame of the Growhaus © II.
First we want to construct the treated wood frame that is a simple 2’ wide X 20’ long, 6-foot high rectangular design. The 2”X 4” vertical “posts” are nailed in at the ends, and at the center line one on each side is an 8’X2”X4” sunk in the soil and inside nailed to the walls of the walk way. This is cross-bracketed about every 2’. Put on two coats of good white paint and have the salesman add a fungicide to the pain at no extra charge. I have found that the Wal*Mart OUTSIDE Latex lasts for several years. I will continue to use their paint.
Next, we take out a heavy duty electric drill and use a ¾” drill bit- I use a Forstner bit but a spade bit works well, but makes a ragged tear on the outside base board, albeit underneath.
You will mark first with a ruler every 2’ and drill a hole. At a 6’ height you will use two 10’x ¾” “plastic” electrical conduit pipes, a total of 22 pipes for this installation at about a dollar each (US) for the ribs. At the top of the 2’ wide wood framework the centerlines of the two married pipes makes a visible marker and it is easy to sight down the top of these bowed pipes (the ends stuck into the holes equally) and adjust them so that you will have a measured distance from one side of the wood base over the top and to the next wood base of ten feet.
Now take your drill, and with a 2” galvanized screw, with an X slot in the tip, and an appropriated drill screw tip, drive the screws into the plastics pipes and secure into the wood frame at the top and on each bottom board. You will use 4 screws per rib.
Your next consideration is the choice of a “window, or light” as it is called in the old trade jargon. For our purposes it is choosing either the clear plastic sheet, a fiber sheeting or fiberglass. Naturally I chose the clear plastic, as it is the cheapest and guaranteed for six years. I want to note that if you take the extra time and a few dollars to install an inside 2nd layer of plastic sheeting, it will last far longer than the outside since the sun’s UV is deflected.
If this design continues to suit me when I recover this unit I will upgrade to a more permanent substance, maybe even polycarbonate sheets.
The two end pieces were ordered as a 10’X11’ each and are each to affix first with a clamp at one end, then stretching to the other, clamping that end then pulling it up to the top, clamping again and working around in a circle. Do both ends.
Then do the big sheet, ordered slightly larger to allow pull over. Centerline and do the same technique. There was a problem for me in that I left the wind turbine cap on and had to make a large cut to slip the plastic over this bulb like dome, and I had a wrinkle. This of course was sealed up with the fiber plastic 2” wide sealing tape, but it was not to my critical observation. Next time I will leave the dome off, make a simple “ x “ cut, then after the entire cover is clamped on and sealed with the wonderful tape, I can slip the dome on and it only is held with 3 screws. I probably would bolt the next one right back against the rear of the frames to make reaching it easier. Keep in mind that moving the turbine, if in fact I find it useful as planned, is easy to move things about. This is not the Empire State Building.
Lastly pull the plastic cover down tight and staple it to the board. I also took 5” guttering and assembled two pieces on each side with a good down angle screwing the metal guttering every 2 feet into the ribs. This goal is to catch rainwater on this roof and channel it the length of the Growhaus© II and make a 90-degree bend and drain it into the 4” protruding pipes that stick up from the underground watering system. Do not forget to use a bit of screening as a leaf trap going down into the underground tubes. Now take a piece of 20’ length of scrap plastic, maybe a foot wide. Take a couple pieces of that plastic sealing tape and stretch it tight a few inches above the gutters. Then seal the 20’ length, place the plastic flap into the gutters and you will capture all the rain and dew. You will require two rolls of the fiber sealing tape.
I have mentioned before that your best source for plastics and construction materials are: http://www.farmtek.com/farm/supplies/home Study the catalog.
Look carefully at the lead-in picture. This will show the construction form, less covering. My camera-who hates me-erased other pictures. Alas, the squash are gone but the peppers are doing nicely, and I see lettuce coming up.
E-mail me in confidence as I do not sell, keep, or trade addresses- I erase them after I have returned your question/answer. email@example.com
COPYRIGHT: 2009, Back2theLand.com, Mark Steel