(my english is not perfect)
this is a portable greenhouse, good for start seeds or small vegetable growing (basil, parsley, salad, cylantro...).
you can move it in the better site of the garden in every seaon, or bring it with you in holiday.
is really really fast and easy to built, and super economic and ecologic, I made mine all out of scraps and in little more than an hour.
1.big plastic can (white is better couse allowed more light in the inside of it);
2.transparent or semi transparent plastic sheet;
3.4 screw with 4 nuts;
4.4 little piece of plywood abuot an inch by an inch;
5.a piece of bike innertube;
7.a slat (long like the can).
Step 1: CUT HOLE IN THE CAN
draw 3 big square on the side of the can(I make them a quarter of the circumference, but if your can is not white, and so not really transparent, even larger). make hole with drill in the corner of the square you draw(pot some tape where you are going to make the hole so that the drill wont slipp away), so that you can fit jig saw in it, and cut along line with it, so you will have 3 open square hole.
Step 2: MAKE HOLE IN THE BOTTOM FOR WATER TO DRAIN
with drill and jigsaw make many hole all over the bottom to let water drain out.
Step 3: MAKE HANDLE
with drill and jigsaw make 2 hole in both of flat side of the can, then pass in hole 3 or 4 row with innertube and make a nut inside. those will be the handles of the green house.
Step 4: PUT PLASTIC SHEET ON CAN
cut big section of sheet, it need to be double, and each side need to be wrapd 3 or 4 time to be strong.
fix one side to the upper part of the square holes (with screws, nuts, small square of plywood and innertube).
on the other side wrap a slat (fix it with ducktape) so will keep the sheet down.
Step 5: YES YOU ARE DONE!
Now put a layer of stone, or BROKEN PIECES OF FLOWERPOT on the bottom of the can before fill it in with dirt, so the wather will drain better. fill it half way with dirt.