English: I found this VESTBY closet from IKEA (discontinued) for free on a Facebook page for my home town. And I got an idea: A greenhouse
VESTBY has matte sheets of plastic on the sides bottom and top, that resembles polycarbonate roofing sheets. It was already almost there.

Materials: Some leftover PE plastic on a roll, some synthetic string and a few nails.

Before:

I measured the PE plastic to fit the front and nailed it to the top of the closet (VESTBY is solid pine).
I also put a few nails in at the top, to which I tied two pieces of string.
And that was it. Dead simple, and now I have a greenhouse.

After:

The closet rod is perfect for tying the supports for the tomatoes to.

Closed for the night or for cold das simply with two square stones:

It can be done fancier than this, but it is perfect for my needs. And it was completely free.

VESTBY is discontinued, but you could do this with other types of closets, bookcases or shelves, and polycarbonate roofing sheets and/or rolls of plastic. Whatever you scavenge.

Dansk:
Jeg fandt dette VESTBY fra IKEA (udgået model) på en lokal salgsside til bortgivning. Og fik en idé.

Idéen er rørende enkel, og krævede ikke andet end en rulle plastic, lidt snor og et par søm.
VESTBY har matte plastplader i sider, bund og som bagbeklædning og det var det, der gav mig idéen. Det mindede om noget
Før, men allerede med sine nye beboere:

Jeg målte PU-plasticen ud (den havde jeg liggende) og sømmede den på foroven på reolen. Jeg bankede også et par søm i, som jeg bandt to længder syntetisk snor i.
Og vupti, drivhus og det har ikke kostet mig en krone.
Garderobestangen foroven er perfekt til snoren til snoretomater. Man skulle tro at møblet var skabt til dette.