A friend of mine, Kirsi, told me about Swedish tradition of white rhubarb. Apparently, the rhubarb is covered from sun and for that it grows white. Then some nice Swedish delicacy is cooked out of it. So I covered my precious bio-organic rhubarb.
And it turned out like this:
Possible reasons for failure:
You should cover the rhubarb earlier in spring
Only Swedish people can do this.
As I've been designing albedo covers, my idea is to shape the cover that is fits perfectly to its' place. My first choice of material was cloth that is used to protect plants from insects and cold (hallaharso). I thought this was perfect fabric because it's light and the plants can grow under it. With starching, you can create the shield, but easily get rid of it if you don't have enough space to store it.
Note to myself: Hallaharso is made out of some sort of space textile and you can't starch it. It absolutely takes no liquid in. Try natural fabrics for natural starching.