The dreaded galinsoga

Thirty plus years ago a gardening friend passed along this tidbit: “galinsoga (Galinsoga parviflora) is the gardener’s weed”.  Galinsoga grows only in cultivated soils such as in your vegetable and/or flower garden from part shade to full sun. It prefers moist soil but grows almost anywhere, even between cracks in a sidewalk. Its thin leaves may wilt in the hot midday summer sun, but recover by nightfall.

The rule is to never allow galinsoga to bloom. It produces abundant seed and those seeds frequently germinate within days, potentially producing multiple generations in one growing season. The seeds overwinter in the soil and become a bigger nuisance in subsequent years.

The hairy leaves and stems grow rapidly to 18-24 inches in height and begin blooming when plants are only 6 inches tall. Tiny 5-petalled white ray flowers surround a yellow disk center. Flowers are less than ½ inches wide.

Hand pulling or hoeing, followed up by mulching, is most effective control measure. Remove galinsoga before it flowers. Seeds already in the soil continue to germinate throughout spring and summer. Pine straw, grass clippings or compost serve as excellent mulches.

Preen® (trifluralin) is a pre-emergent herbicide for garden use. Read and understand the label before using.