Galinsoga parviflora aka Quick Weed

Galinsoga parviflora is an annual in the sunflower family. Common names include gallant soldier, quickweed, and Kew weed. In Colombia, people know it as guascas. Kew places its native range from Arizona and Texas through tropical America. It has spread far beyond that range. It now grows in both warm and temperate regions. It is not native to Britain or Ireland.

This slender plant grows quickly and stays fairly small. Garden size is about 1.6–2 feet (0.5–0.6 m) tall. Its spread reaches about 1.3 feet (0.4 m). The wider reported height range is 0.7–2.3 feet (0.2–0.7 m). Leaves provide its main food crop, though people also eat stems and shoots. Older stems can become tough and hard to chew. Flowers appear from May to October. Each flower has both male and female organs. Insects pollinate the flowers, but the plant can also fertilize itself.

It grows in fields, gardens, orchards, and along roads. It also takes root in waste ground and pavement gaps. Fertile, moist soil supports its best growth. It accepts sand, loam, and clay, with good drainage preferred. It grows in mildly acid, neutral, or mildly alkaline soil. Full sun and partial shade both suit it. PFAF lists USDA zones 5–11. Growers can sow seeds in place during spring. Seeds usually sprout within a month.

Its fast growth and heavy seed crop make it weedy. A plant may produce several thousand seeds. It can go from sprouting to shedding seeds in 50 days. Even very short plants may set viable seed. Fallen seeds can sprout soon after reaching the ground. Irrigation and year-round rain can support dense stands. These stands cover bare soil but may need control. The flowers feed small insects. Birds and other wildlife may eat the seeds.

People eat the leaves fresh or cook them as greens. They also add them to soups and dry them for seasoning. Guascas has a place in traditional Colombian soups. Flowers can provide an herbal tea. Wash leaves well and avoid plants from polluted soil. Avoid diseased plants and tough, old growth. Sources record folk uses for nettle stings and wounds. These reports do not establish that such treatments work. Both plant-use sources warn that goats may suffer poisoning.