Pre-emergent weed killers work as a prophylactic to prevent seed germination. Once the weed seed has germinated they are no longer effective and you will need to confront weed problems by pulling up the weeds by hand or by using a post emergent herbicide. My favorite pre-emergents for use in flower beds feature Treflan or Dimension. My favorite pre-emergents for lawns include Barricade or prodiamine, Dimension, Treflan, Balan or Sulfentrazone. For those trying to go organic you can use 60 percent powdered corn gluten meal. Make sure to read the directions on whatever pre-emergent you choose before application. Most require a good rain or watering the equivalent of a half-inch after application to activate the product.
Get your gardening boots on, start planting cool season vegetables.
Rodd Moesel serves on the Oklahoma Horticulture Industrial Council and the Oklahoma State University agriculture dean's advisory committee. Email garden and landscape questions to firstname.lastname@example.org.