Common names: Dandelion, lions-tooth, blow-ball, cankerwort, Irish daisy, pee-a-bed, wet-a-bed
Latin name: Taraxacum officinale
Family: Asteraceae (Aster family, sunflower family)
Life Cycle
Dandelion is a perennial weed that reproduces by seed. Seeds germinate in spring and summer, and seedlings form a rosette (Figure 1). Dandelions begin flowering in their second year of growth, with concentrated flowering from April to May in Indiana and sporadic flowering until the first fall frost. Viable seeds are set just days after flowering. Dandelions overwinter by storing carbohydrates (plant food) in their large taproots (Figure 2). This stored “plant food” is used for spring growth and development. This seed-propagated perennial life cycle allows dandelion to effectively reproduce and maintain large populations.
Figure 1. Dandelion seedling rosette (Photo by Celia Corado).
Figure 2. Dandelion taproot (Photo by: Celia Corado).
Identification
Leaves
The first true leaves are alternate, hairless, teardrop shaped, and have gray-green on their lower surface (Figure 1). Young leaves are oval-shaped with a long petiole and lack hairs. By the third true leaf, margins are wavy with irregular, widely spaced teeth. Older leaves can have some appressed crinkled hairs on upper and lower surfaces (Figure 3) and widely spaced teeth pointing toward the leaf base (Figure 4). When cut, leaves, flower stalks, and the taproot exude a milky white sap (Figure 5).
Figure 3. Scattered hairs are sometimes found in the midvein and undersurface (Photo by Celia Corado).
Figure 4. Dandelion rosette habit. Note the widely spaced “teeth” of the leaf pointing toward the base of the plant (Photo by John Obermeyer).
Figure 5. Dandelion exuding milky white sap after being cut (Photo by Celia Corado).
Flowers and Seeds
A dandelion “flower” is actually a composite of hundreds of smaller flowers. The flower head (Figure 6) consists of 100-300 yellow-petaled flowers, each with five points at the tip. Although their flowers are a source of nectar for spring pollinators, dandelion flowers do not require pollination to develop viable seeds. The seed head is gray-white and spherical (Figure 7). Each seed contains a pappus, the plant equivalent of a parachute, that allows the seed to be carried in the wind.
Figure 6. A dandelion inflorescence (flower head) consisting of hundreds of individual yellow flowers (Photo by John Obermeyer).
Figure 7. A dandelion seed head containing hundreds of mature seeds, each with its own pappus (parachute) (Photo by John Obermeyer).
Fun Fact
Dandelions are edible from flower to root. People have used dandelion flowers for wine, and the roots can be roasted and used as a coffee substitute. Dandelion leaves can be used as a salad green.
Management
Dandelions thrive in no-till and reduced tillage production settings, suggesting that tillage is a viable means of control. Because of its low growth habit, mowing is not an effective option. Here are some other weed control options for dandelion:
- Cover crops: Utilize cover crops to outcompete dandelion for resources and provide a physical barrier to its growth. Because dandelions are low-growing, there are many options for cover crops that can overtop the dandelion canopy. And because dandelions are perennial, effective use of cover cropping is not limited only to fall-planted species. For help choosing a cover crop, we recommend the Midwest Cover Crop Council selector tool: mwcc (midwestcovercrops.org)
- Plastic mulch: Acting as a physical barrier, plastic mulch hinders germinating dandelion seedlings from reaching the soil surface. Ensure that planting holes are sized to fit only your transplant. Excessively large planting holes can allow weeds to emerge next to the crop.
- Cultivation: Frequent cultivation, with tine weeders, for example, can effectively remove dandelion seedlings as they germinate. Take care not to uproot your crop. Tine weeders work best when dandelions (and other weeds) are at the white thread stage and just germinated. More aggressive cultivators can be used for established seedlings.
- Plant-based mulch: Whether you use leaves, wood chips, or straw, plant-based mulches can stop dandelion seedlings from emerging. A thick layer can also cover and kill mature plants. However, dandelion seeds that land on top of these mulches can still germinate and develop.
- Silage tarps: Silage tarps prevent germinating weeds from receiving sunlight. Although they will work well for dandelion seedlings, they will be less effective against established dandelion plants (and perennial weeds in general). Extended tarping will be necessary for acceptable control.
- Hand-weeding, hoeing, and cultivation: Dandelion seedlings can easily be removed by hand or hoe, but established plants will require the removal of the taproot for complete control.
- Flame weeding: Use flame weeding to control dandelion in its seedling stage. Flaming will not control dandelions that have an established taproot.
- Herbicides: The best time to control dandelions is in the fall when the plant is moving resources into its taproot in preparation for winter. Apply systemic, post-emergence herbicides after a light frost but while dandelions are still actively growing. Broadleaf-selective herbicides, such as 2,4-D, can be very effective. Visit the Midwest Vegetable Production Guide (mwvegguide.org) to learn which herbicides are labeled for the crops you intend to grow.
References
Mohler, C., Teasdale, J., & DiTommaso, A. (2022). Manage weeds on your farm.
Neal, J., Uva, R., DiTomaso, J., & DiTomasso, A. (2023). Weeds of the Northeast (2nd ed.). Cornell University Press.
Patton, A. J., & Beck, L. (2020, 5 febrero). Dandelion. Turfgrass Science at Purdue University. https://turf.purdue.edu/dandelion/