When do i apply broadleaf killer

Fall is an excellent time to apply broadleaf herbicides for perennial broadleaf control, but take care to do it properly and effectively. Iowa State University Extension and Outreach horticulturists can help answer questions about the right time and methods to apply broadleaf herbicides.

Fall mid-September to early November is the best time to control perennial broadleaf weeds in the lawn with broadleaf herbicides. In fall, perennial broadleaf weeds are transporting food carbohydrates from their foliage to their roots in preparation for winter. Spring applications are less effective than fall applications. The most effective broadleaf herbicide products contain a mixture of two or three herbicides, as no single compound will control all broadleaf weeds.

Warm spring temperatures, winds and succulent plant growth can create problems for trees, shrubs and flowers often damaged by the herbicide drift. Cooler fall temperatures and the dormant state of most plants greatly reduce this problem. In the spring, the lawn should be relatively weed-free without undesirable bright yellow dandelions, purple henbit and lime-green chickweed.

With properly timed weed control, the lawn will be a carpet of dark green, a proud site for the homeowner! Have questions? Sign in. Monday - Friday, a. Chickweed Reasons for treating for broadleaf weeds in the fall Broadleaf weeds such as dandelions, henbit and chickweed all germinate in the cool, moist periods of September and October. Phone: Email: garden. Wear protective clothing, including long pants, a long-sleeved shirt, gloves and safety goggles, when applying weed killers.

Pre-emergent weed killers control annual lawn weeds while they sprout, which means the herbicide must be on the lawn before the seeds begin to germinate. Annual plants grow during one season, and then set seed and die. Summer annual weeds like crabgrass Digitaria Haller and goosegrass Eleusine indica germinate in the spring and winter. Annual weeds like common chickweed Stellaria media and henbit Lamium amplexicaule sprout in early fall.

Consequently, to control summer annual weeds, apply a pre-emergent weed killer in early spring, and to control winter annual weeds, apply a pre-emergent herbicide in early fall. If you can already see annual weeds in your lawn, it's too late to apply a pre-emergent herbicide. Post-emergent weed killers are most effective when the weeds are actively growing. Selective post-emergent herbicides target certain types of plants, like perennial broad leaf weeds like dandelion Taraxacum officinale and plantain Plantago major or annual weeds, but don't harm turf grass.

This allows sufficient time for the broadleaf weeds to absorb the herbicide and translocate it to their roots. You are here Home. What is the proper way to apply broadleaf herbicides to the lawn?