Galinsoga quadriradiata traveled far from its origins in South America and central Mexico to become one of the more widespread summer weeds in gardens, agricultural fields, and planting beds across the northern hemisphere. It arrived in Europe centuries ago via botanical gardens and has since made itself thoroughly at home wherever the soil is disturbed and nitrogen is plentiful. The plant is not without a certain ragged charm: coarsely hairy stems two to ten inches tall carry small flowers with five white rays around a yellow disc, producing the minimal but recognizable daisy structure of its family. The ovate, toothed leaves are hairy throughout.

Its real talent is speed. In warm weather it germinates, grows, and sets seed with remarkable efficiency, forming colonies quickly and reseeding aggressively before most gardeners have noticed it is there. The preference for moist to dry conditions, full or partial sun, and fertile loam makes it adaptable across a wide range of garden situations. Control is straightforward while plants are small — hand-pulling before flowering begins, followed by mulching to suppress subsequent germination. The critical mistake is allowing it to set seed: a single plant can produce thousands, and the hairy seeds disperse readily. In beds with high nitrogen from fertilizing regimes, population pressure can be significant.