Dandelions; love them or leave them, but don’t spray them
It’s really all about marketing.
If you despise dandelions with a burning passion and feel compelled to do something now, let’s take a quick look at what is going on underground. The dandelion’s long taproot stores energy gathered in the summer through mid-fall. In spring, this energy moves upward supporting new growth and flowers. To kill the plant you must kill the root. Herbicides applied now will kill the tops, but since the momentum continues upward, little to none will reach the root. Later, as the growing season begins to end, energy flows downward to be stored in the root in anticipation of next spring. Herbicides applied then find their way into the root with a greater chance of killing the plant.
So disregard the marketing encouraging you to apply herbicides now for dandelion control. If you’re itching to do SOMETHING, have no fear. There are effective strategies you can do now that will discourage weeds, not just dandelions, while building a stronger, healthier lawn. For more information, visit Cornell University’s Lawn Care Library.
For more information on what to consider before choosing herbicides, visit the NYS IPM Program’s webpages: Weeds and Your Lawn: Are Herbicides Really Necessary? and A Method to Measure the Environmental Impact of Pesticides.
Source: cornell.edu
