Aiken residents looking to reduce seasonal allergies this fall should focus on preventing ragweed from spreading, especially as the plant begins to bloom in early August to September. Ragweed is a common cause of seasonal allergies, producing billions of pollen grains in a single season, and can quickly take over yards if not managed.
Michelle Wiesbrook, an extension specialist in weed science at the University of Illinois, advises identifying ragweed early and preventing it from going to seed. A single plant can produce thousands of seeds, making early intervention crucial. Regular mowing with a lawnmower or strimmer, particularly before the plants bloom, can significantly reduce pollen loads. Since ragweed grows quickly and can re-bloom after cutting, consistent mowing until the first fall frosts is essential.
Beyond mowing, consistent weeding is another effective method to drastically reduce ragweed in yards. Young plants are easiest to remove as their roots are not yet well-established, but pulling or digging older plants is still beneficial to prevent seed dispersal. To further deter ragweed and other opportunistic weeds, covering bare soil is recommended. Wiesbrook suggests using a 2 to 3-inch layer of mulch in garden beds or planting ground-covering plants like moss phlox, wild ginger, or native foamflower.
For lawns, practices that encourage dense plant growth can help grass compete with weeds. This includes interplanting grass with clover, dethatching and aerating to improve grass health, and addressing turf diseases that create patchy areas. If large areas of ragweed have already invaded, tarping can be used. This involves mowing the ragweed close to the ground, spreading heavy, dark tarps over the area, anchoring them, and leaving them in place for 6 to 8 weeks during the growing season. This technique smothers roots but will also kill other plants underneath.
Ragweed seeds are notably long-lived, remaining viable in soil for 20 years or more. Soil solarization, using clear plastic sheeting during warm weather, can cook these seeds and prevent sprouting. After mowing plants down and moistening the soil, anchor the plastic sheeting for 4 to 6 weeks. For small patches, horticultural vinegar sprays, which have higher acidity than kitchen vinegar, can be effective on young ragweed plants, but should not be used if plants are about to bloom or drop seed. Finally, practicing no-till gardening and gentle weeding minimizes soil disturbance, preventing dormant ragweed seeds from being brought to the surface where they can sprout.
