How Can I Control Dandelion?

Do you have a dandelion invasion in lawn or turfgrass?

Do you want to control dandelions with herbicides?

Do you want to prevent dandelion invasion in landscape areas?

Do you want to control dandelion invasion with organically accepted products?

Spot-spraying isolated plants with translocated herbicides (glyphosate, triclopyr, 2,4-D, dicamba, MCPA, mecoprop, and others) can be helpful. Glyphosate is a nonselective herbicide that will kill turfgrass, leaving open areas, while the others will not injure most grass species. Triclopyr should not be used on Bermudagrass or other warm-season turf species. Overseed any open spots with grass seed similar to the existing turf species to reestablish a vigorous lawn. Some preemergence herbicides such as those containing dithiopyr or isoxaben have been effective in managing dandelions.

No single control procedure has been successful in controlling dandelion in turfgrass. Early grubbing of new seedlings should be practiced diligently and regularly for several years to successfully reduce the dandelion population. Solitary new dandelion plants along fence rows, roadsides, flower beds, and turfgrass should be grubbed out (removed by digging out the entire plant, taproot, and all) before they produce seed. Dandelion knives and similar specialized tools are available for removing individual weeds and their roots while minimizing soil disturbance.

Mulching with landscape fabrics can be particularly effective for controlling seedlings, reducing the amount of light that can reach the soil. Use polypropylene or polyester fabric or black polyethylene to block all plant growth. Fabric mulches should be covered with mulch (wood chips, bark, or other materials) to improve aesthetics and to reduce photodegradation. Mulches such as wood chips or bark may also be effective if they are maintained at a depth of least 3 inches deep. If these materials are used without a landscape material, additional wood chips will need to be added as the mulch layer breaks down over time.

Organically accepted products are contact herbicides and will only affect the part of the plant directly sprayed. Many of these products are botanically based oils (e.g., clove oil, eugenol, and d-limonene), or fatty acid soaps (e.g., pelargonic acid and nonanoic acid), or acetic acid. These products control weeds by destroying the leaf cuticle or causing cell leakage that rapidly leads to plant death. They may control small dandelions but will not control established perennial plants and have no residual activity so seeds that germinate after application will not be controlled.

The preemergence herbicides isoxaben, indaziflam, and oxyfluorfen applied to the soil before dandelion seeds germinate have been useful in limiting infestations. Because of the dandelion's extended germination period, the area must be monitored regularly to determine when the herbicide must be reapplied. If isoxaben or indaziflam are used without postemergence herbicides, be sure to remove all existing dandelions and lightly hoe any seedlings that emerged after the application. If oxyfluorfen is used, do not disturb the soil after application.