The developmental status of perennial weeds such as rush skeletonweed (Chondrilla juncea L.) can influence herbicide absorption and translocation. Differential efficacy between fall and spring applications suggests vernalization impacts herbicide absorption and translocation in other perennial asters. Clopyralid and aminopyralid absorption and translocation were quantified in nonvernalized and vernalized plants following application of ¹⁴C-labeled herbicides 2, 4, 8, 24, and 72 h after treatment. Less ¹⁴C clopyralid was absorbed, and at a slower rate, in vernalized plants. Movement out of the treated leaf was slower, with ¹⁴C clopyralid translocating more rapidly than ¹⁴C aminopyralid. More ¹⁴C moved to the roots in nonvernalized plants compared with vernalized plants, regardless of herbicide. Increased translocation to belowground survival structures is needed for effective control of C. juncea.