Miro Geenhouse

Build a Micro Greenhouse

This greenhouse is 3' deep, 8' long, and 5' tall. In this climate the greenhouse will be great for keeping greens and such going in the coldest part of winter, but the real benefit we will reap is to propagate tomato, pepper, and eggplant starters. We will use the grow light set-up to get them started and transfer them to the greenhouse in March and April in preparation for planting in early May in our garden. Cost- about $100.00. Time to build- 3-1/2 hours.

A "hoop" Micro Greenhouse

5- 10' pieces of PVC 3/4" schedule 40 conduit sawn in half
5- 90 degree PVC 3/4" Sch. 40 90 degree elbows
1- 20 pack of 3/4" conduit clamps
3- Pressure treated 2"x6"x8' boards
10- 18"x1/2" rebar
10'x25' clear 6 mil plastic
3" and 1-1/4" decking screws
PVC Cement- check to be sure it is the right cement for this kind of PVC!
3- 8' pieces of 1/4"x 2" lathe
2- 2"x4"x8' boards
12 tarp clips
6 bungees or straps

The Greenhouse needs to face South! The door is the side that is held down with 2x4's and is the south side!!!

The wooden frame

Cut one of the 2x6's into two 3' lengths, and the remainder of the cut 2x6 should be cut into four 5-1/2" lengths. Use the 5-1/2" pieces as corner blocks on the inside (see photo). Screw the corner blocks flush at the ends of the 3' 2x6's, then screw the 8' 2x6's to the 3' 2x6's and blocks making sure the long boards are flush at the ends of the short boards. Use 3" decking screws to screw it all together.

Making the hoop Frame

Start by marking the long legs of the wood frame every 24" (on the outside of the frame on both long sides). The first and last mark should be set about 1-1/4" in from each end. Drive the rebar into the ground directly in front of the mark about 1/2" away from the mark on the board leaving the rebar sticking out of the ground about 5-1/2" (it happens that this will be flush with the top edge of the wooden frame)- later the conduit will slide over the rebar. Be sure the rebar is square and parallel to the wooden frame leaving a small space between the rebar and frame so that when you slide the conduit onto the rebar the conduit is very close to the frame.

The conduit should be cut in half so that each 10' piece yields two 5' pieces and be sure to keep them paired up. Each 10' piece will yield a matched pair! Notice that one of these has a fat end, this is so that the parts can be fitted together. Take the piece with the fat end and put the pvc glue using the built-in applicator inside the fat portion of the conduit- slide the skinny side of the 90 degree pvc elbow firmly onto the glued fat side and give it a good twist (see photo #4). Put more glue onto the fat side of the pvc elbow and slide the the piece that has NO fat end firmly into the joint. Give it a twist. Repeat this with all of the rest of the conduit and elbows. You should get 5 "V" shaped conduit sections.

Slide one side of your conduit "V" over one of the rebar stakes, pull the other side of the "V" onto the opposite stake and you should have one section that looks like the profile in photo #1. If this looks right repeat this with the rest of the "V"'s.

Take the conduit clamps and slip them on so they look like the detail in photo #3. Inspect all of the "V"'s to make sure that they are square and even. Stand at the end and look down the row to make sure the "V"'s line up. The sections can be adjusted by pushing or pulling them into line. If it all looks good screw the pvc clamps to the wooden frame as shown in photo #3 using 1-1/4" decking screws.

Finishing the frame

Take an 8' piece of 1"x1" wood (I used a scrap) and lay it across the tops of the "V"'s and see if it lines up. Don't worry if it isn't perfect! Drill a hole from the bottom through the apex of the "V" and into the board above. take a 1-1/4" decking screw and drive up through the elbow into the hole you drilled in the board (see photo #4).

Clear plastic sheeting

Cut the plastic sheet into 1- (top) 10'x12' piece and 2- (ends) 6'x5' pieces.

Pulling the plastic sheeting tight at every step will keep it from flapping in the wind- it will look better and it will last longer!!

The 5'x6' end pieces of the plastic sheeting should be pulled up so that they extend above the top of the PVC frame about 6" and the sides extend past the wooden frame about 6" on each side. Using a 4' piece of predrilled lathe screw the lathe through the plastic and into the wooden frame close to the ground. Be sure to leave 3" of the plastice hanging down below the lathe.

Pull the plastic tight and wrap it around the end frame. Trim it so that it leaves about 6" inside of the end frame when you look at it from the inside. Take some lengths of duct tape- and from the inside, tape the end from side to side all the way from frame to frame while pulling the plastic tight. Do this in about 5 places (about every foot). Go all the way around the end frame and loop back so that you make a sandwich around the end frame with the plastic and tape (see photo #5). Pull it tight as you go!!!

Plastic sheet for the top

The North side is the back of the greenhouse. Pull the plastic sheet over the greenhouse so that you will have about 3" extra on the North side, 1' extra on each of the side panels (where you already put plastic and about 1-1/2' extra on the south side.

In photo #5 you can see that we trimmed the top panel so that you will have about an etra foot of plastic extending over the side panels. On the right (South), you can see two 2x4's holding down the plastic to keep it closed up.

Go to the North (back) side and starting in one of the middle sections screw a piece of 1/4"x2" lathe about 20" long onto the plastic and into the frame close to ground level. Leave about 3' of the plastic hanging below the lathe. Work your way toward the ends one section at a time pulling the plastic tight and making sure you leave the plastic hanging down 3". Pull the plastic tight from the South side and put the 2x4's on top to keep it tight.

Take the 8' section of 1/4"x2" lathe and line it up with the 1x1 board at the top of the frame- you can see it in photo #4 and photo #7. Predrill the boards one screw hole at a time and drive the screw before moving to the next screw. Offset the screws so that you don't screw back through the PVC frame. Remember to pull the plastic tight before you drill each hole!

#1- The finished greenhouse

#2- The wooden frame

#3- PVC frame detail

#4-More framing detail

#5- Plastic Detail

#6- Detail of the back side (North)

#7- Lathe installed on ridge

#8- View of the finished greenhouse

from the front (South side)

Finishing the Job!

I use Tarp clips to keep the top sheet of plastic tight. Put some Duct tape on the plastic sheet where you will be putting the clips to reinforce the plastic. Three pairs of clips on each end should be ample. Use bungees or straps on the clips to keep the plastic tight (see photo #5).

To keep the front closed I use 2- 2x4's. Pull the plastic tight and there should be a little more than a foot on the ground on the front of the greenhouse. put one 2x4 on the plastic about 1-1/2" from the frame, pull the plastic over it and put the other 2x4 over the plastic in the space between the frame and the first 2x4, locking it all in place!

You are done!