California Pest Rating for False Yellowhead | Dittrichia viscosa (L.) Greuter Asteridae: Asteraceae Pest Rating: A  |   Proposed Seed Rating: P PEST RATING PROFILE Initiating Event: False yellowhead (Dittrichia viscosa) has been rated as “Q” on the CDFA Plant Pest Rating since 2014. This plant is on the “Alert list” for Environmental weeds in Australia. … Continue reading False Yellowhead | Dittrichia viscosa (L.) Greuter →