To prepare dandelion.

Roots are on early spring till a herb blooming,as on April-May beginning, and autumn on September-October on a leaves bad.
They shake,as clean,dry in oven,as cracking with breaking and dark brown color, bitter taste, non-smell, mucus, for a five years keeping in packets paper, and summer roots are not effectivity, less benefit substances , leaves preparing on all vegetative stage, as far away from a roads,factories, on early spring, far away,as a roots, on a morning after  dew drying  as flowers .