Dyers woad reproduces mainly by seed but may resprout from buds located at the crown. Seed production is prolific and typically occurs from late May through July in California. Seed remain within the fruits and are mainly dispersed by animals, human related activities and water. The role of rodents and birds in dyers woad seed dispersal is uncertain. Dyers woad has frequently spread via contaminated hay and alfalfa, and on mowing and harvesting equipment.
Invasions initially occur along roadsides and then move into adjacent fields or rangelands.
Eliminating solitary plants along roadsides is critical to avoid larger problems. Additionally avoid carrying contaminated hay into backcountry areas where dyers woad does not occur. However, hand pulling may be very effective in reducing infestations. It is critical to remove the crown to prevent resprouting. Hand pulling is easiest after the plants have bolted but should be done before seed set.