Blueweed, known botanically as echium vulgare and more commonly as viper's bugloss, is a flowering biennial herb that produces blue flowers in summer from June through August. It thrives in undisturbed pasture lands and fields, by the sides of roadways and other dry areas with poor soil conditions. Blueweed's foliage has a furry appearance and pale cream speckle detail. It is considered an undesirable invasive species in many regions.
Water your blueweed deeply several times in the fall before the first frost hits. Watering well will help fortify the surrounding soil and your blueweed's taproot against the stress of winter drought conditions. Water around the base of the plant and not over the leaves to reduce the chance of disease.
Cut back your blueweed to removed any damaged or dying flower spikes and branching in the fall after the first frost. In climates where the top foliage does not overwinter, shear the plant down to the crown to prevent rot during the winter and prepare space for fresh spring growth. In the spring prune away and plant material that was damaged over the winter.
Mulch around the base of your blueweed or over the sheared crown with an organic mulch material in the fall after a deep watering. Use compost, shredded bark, wood shavings or cocoa bean hulls laid down at least 2 inches thick for the best protection of the plant's taproot from cold winter temperatures and drying winds.