Rhizome thick, small-branched, scaly. The roots of the oleander are harvested in September-October after the aerial part has died or in early spring (in April) with the beginning of the growth of young leaves. They dig out
raw materials with shovels (diggers) or plow them
plows (on large areas). After that, the roots are removed from the ground, the above-ground part, rotten parts of the rhizomes and small roots are cut off. Raw materials are washed in cold water and dried in the open air for several days. Then the rhizomes are dried under a canopy, in an attic with good ventilation or in dryers (ovens) at a temperature not exceeding 50-60° C. Spread the raw material in a thin layer on trays or on grids. Dry rhizomes are stored in well-ventilated rooms.