Application rates may need to vary markedly depending on the type of soil that the chemical is being applied to. For organic production, mulching will suppress weeds and a flame weeder could also be used. Dandelions are little troubled by pests and diseases. Roots can suffer from a dark coloured root rot but this is not common. These trial figures are for graded, washed roots that have had all leaves removed and any diseased portions of the roots removed.
Harvesting There is debate about what is the optimum time to harvest dandelion root.
Some believe the roots to be more bitter when harvested in autumn but others consider the roots to be more bitter in spring. Chemical components of the root vary depending on the seasons. When collected in spring, food reserves from the root have been used up for the production of leaves and flowers and the root may have a shrivelled and porous appearance when dried. If growing roots specifically for dandelion coffee, it is recommended that you harvest in autumn, although you may be able to extend the harvesting season through winter. Bitterness is a natural characteristic of dandelion.