Historically, dandelions were appreciated and even cultivated, but most modern gardeners consider them a nuisance. Chemical herbicides may control weed growth, but they also pollute groundwater and leave toxic chemicals on the lawn. Instead, organic gardeners maintain healthy lawns through proper watering and mowing practices and by cultivating an attitude of tolerance, instead of expecting lawn perfection.
Dandelions are perennial, broadleaved weeds. While never completely dormant, they grow little during the winter, but re-emerge in early spring. The plants have a long taproot, making them difficult to eradicate. The yellow, multi-petaled flowers bloom from mid-spring to late summer. As the flowers mature, they produce a rounded, feathery seed head.
Dandelions were cultivated as a food crop in ancient times. They were used medicinally in monasteries, according to Montana State University, and were grown by Anglo-Saxons to prevent scurvy. Puritans brought them to North America in the 1630s and used their greens. All parts of the plant are eaten, including the roots and flowers. Dandelion cuisine includes roasted roots, steamed greens, dandelion tea and dandelion wine. The plant is high in many nutrients, such as iron, copper and potassium.
Organic Weed Killer
Several organic weed killers are available for use on dandelions. Clove-oil based (eugenol) herbicides are very effective, according to the National Gardening Association. Acetic acid, found in vinegar, is also effective on many broadleaved weeds, as well as grasses. Household vinegar contains 5 percent acetic acid and is less effective than commercially produced products, according to Pennsylvania State University Extension Service. Herbicides work best on young plants and may require repeated applications. Gardeners should apply them when the weather is dry and sunny, with temperatures above 70 degrees F. Corn gluten is an organic pre-emergent that is spread before dandelions emerge in the spring. It works best when applied for several years.
Digging out dandelions requires a dandelion fork or other tool to remove the long, tough taproot. Flaming with a hand-held propane flamer scorches the plant's tips and causes the water in the plant's cells to boil. Flaming is most effective on young plants and causes their leaves to curl up and die within two days. Pouring boiling water on dandelions is another common method. Flaming and hot water can damage surrounding plants, so use with care.
Maintaining a healthy lawn through good cultural practices will minimize--if not eliminate--dandelions in the garden. Lawns should be mowed high to keep grass healthy, according to Cornell University, and given long, infrequent waterings. Gardeners should apply fertilizer in the fall, rather than the spring, for cool-season grasses. The most important task in minimizing dandelion invasions is removing the flowers before they go to seed.