Dandelions are hardy perennial plants. They can germinate throughout the growing season, and as a result, can be found in various stages of growth during the summer. Growing dandelions are especially productive in the spring as they can take advantage of early starts to utilize moisture and nutrients and complete their reproductive cycle before many other plants. While most people get concerned about dandelions when they are in the blooming phase, this is the time when they are most difficult to control.

• Early blooming perennials such as dandelions need to store energy in their roots. When soil temperatures warm up in the spring, they draw on these reserves to generate top growth and bloom resulting in the upward net movement of material in the plant, away from the root. As a result, spring-time herbicide application doesn’t accommodate any deep translocation into the root system, instead it only provides top growth control.
• One of the hazards of herbicide control is the potential for drift damage on non-target plants. When the leaves on trees and bushes begin to change color, it is a sign that the tree is preparing to cast the leaves for winter. This is the best time to spray for dandelions as the surrounding trees and bushes are no longer able to take in any herbicide as they are essentially dead tissue.
• As dandelions remain active much longer than most other plants, applying herbicide controls in the fall allows you to catch dandelions at their most vulnerable stage, limiting potential damage to surrounding trees and plants.
• Most of the herbicides registered for dandelion control are volatile, meaning heat can cause them to vaporize off of the ground, causing off target damage. Cooler fall temperatures combined with the fact that most vegetation is dormant provide the safest window for herbicide application. This doesn’t mean that you can apply herbicides on all plants and not expect damage. Avoid the direct application to any plant that you do not want to kill, but small amounts of drift will not impact dormant plants.
• Another benefit of fall herbicide application is the cooler temperatures control the herbicide from evaporating, which in turn controls the odor associated with herbicides.

Fall herbicide applications in combination with good fertilizer programs will give your lawn or pasture the competitive advantage against dandelion infestations. And best of all, you will see limited blooming in June when everyone else is trying to get a handle on these problem weeds.