Do you want to prevent weed infestations in your beds? Control the invasion of unwanted plants in gravel driveways and pathways? Keep annual weeds from colonizing your lawns? Save yourself time and energy by investing in pre-emergents!
Pre-emergents are chemicals which prevent weed seeds in the soil from germinating. They range from gentle, short term control (such as Preen for flower beds) to more aggressive, long term solutions (such as Casoron for shrub beds and driveways). A variety of pre-emergents are widely available for homeowners, depending on your needs.
Pre-emergents are typically applied early in the growing season, and must be applied before weeds begin to grow. They normally consist of a granular formula and are broadcast over the area in need of treatment, at a rate specified by the manufacturer.
A critical step in applying pre-emergents is to water them in and/or lightly apply mulch over them (in the case of beds) to hold them in place. This is important because wind can translocate (move) chemicals from their desired locations to undesirable locations. For example, while preventing weeds from growing in your garden pathways is important, you do not want to prevent your vegetable seeds from growing by allowing the pre-emergents to drift into your planting beds! As with any chemical, follow all safety instructions and only use them in the quantity, and for the application, specified. Use extreme caution any time you are working near waterways.
The proper use of pre-emergents can be highly beneficial and save a lot of labor, especially in areas of high visibility or where annual weeds are a problem. By breaking the weed cycle, you will, over time, minimize the soil seed bank, thereby greatly reducing the incidence of annual weeds.