the verbascum genus brings together about three hundred species of perennial and annual herbaceous plants, originating in Europe and Asia; some species are widespread also in Italy, even as weeds, such as V. thapsus, called Tasso barbasso. V. chaixii produces a thick rosette of dark green, rough, lanceolate leaves, even 30-40 cm long; in summer, until autumn, from the rosette of leaves develops a thick erect stem, which bears a panicle of star-shaped flowers, white or pink; there are numerous hybrids of more varied colors, with pistils in contrasting colors. Generally they begin to bloom starting from the second year after the development of the basal rosette; the stem bearing the flowers can reach 150-180 cm in height.
The specimens of mullein in place of the sunny garden where they can receive at least a few hours of direct sunlight during the day; in fact, the mullein it cannot bear to be grown in shady areas, since, in this case, it cannot grow and develop at its best and does not produce flowers. The plants of verbascum they are rather rustic and resistant, for this reason, they are not affected by the lower temperatures and the harsh climate of the winter season, being able to be cultivated outside without particular cultural precautions.
In general the mullein is satisfied with the rains, even if it is advisable to water the plant in case of prolonged drought, especially in the summer season, when the external temperatures are quite high, a phase that coincides with the flowering period; in this way it is ensured that it is more vigorous and lasting.
It is good to check that the water supply does not cause the formation of water stagnations that are harmful to this kind of plant.
During the cold months the specimens of verbascum they do not need watering and they can be suspended.
The specimens belonging to this variety, given their good rusticity, develop well in any soil, as long as an excellent drainage of the water is guaranteed since the water stagnations turn out to be harmful for this variety.
Verbascums generally tend to develop best in poor and stony soils requiring nothing more than a good degree of drainage which avoids too moist soils.
The multiplication of these perennial plants generally takes place by seed; the plants produce dozens of fertile seeds every year and do not present particular difficulties to be cultivated, developing with great ease. The seeds can be placed directly in the ground where they are to be cultivated, without having to set up a seedbed.
Mullein - Verbascum: Pests and diseases
Given the great rusticity of this kind of plant, it is unlikely to be affected by pests or diseases if in the correct growing conditions; in damp places the plants tend to deteriorate rapidly as water stagnation or excessive humidity cause the formation of root rot which can be very specific for this type of perennial plant.