In the war against weeds there is a secret weapon I turn to twice a year to make my battle easier to win. It is a preemergence herbicide. Without it I can tell you the weeds would have taken over long ago. I consider my landscape to be low maintenance. But low maintenance is not no maintenance, and in an effort to keep the garden sustainable, preemergence herbicide is a must. It is a naive gardener who thinks they will permanently get a handle on the weed issue without it.

I think it is worth taking the time to understand when, where and how to apply this product.

Timing is important when applying a preemergence herbicide. Any time you disturb the soil in your garden you bring new weed seeds to the surface where they will take the first opportunity to sprout. All they need is a little moisture and a few sunny days and they are off and running. We usually don’t even notice them until they are already getting out of control. Spray in fall and again in spring. Spacing your applications about six months apart, and using the strongest mix suggested on the label.  It needs to rain within 30 days of application (if you use my favorite brand – Weed Impede). If there is no rain for 30 days you need to wet the area you sprayed. You can use the hose or set up a sprinkler, whatever method you like, but the chemical is activated by water. If you are clearing a new area to be landscaped at another time of year by all means use a pre-emergent then, as a deterrent to the weed seeds which are just waiting to choke out your newly installed garden.

If you missed the window of opportunity in fall it is not too late to apply now, before the rainy season gets in full swing!

Preemergence herbicides control annual grasses and many broadleaf weeds in all established garden beds, and non-planted areas alike. I spray it on my decomposed granite pathways and into my garden beds.The way this herbicide works is by killing the plant root as the seed germinates. It does not kill existing plants, and if there are weed roots left by pulling or hoeing out weeds those may still sprout a new weedy top. Preemergence herbicide only works on seeds. There are a few ornamentals that should not be sprayed with preemergence and you will find a list of those on the container. There are also granular preemergence products which generally have to be applied every three months. Whichever type of preemergence herbicide you use follow the directions carefully and you will begin to win your war on weeds!

What do you think? What has your experience been with a preemergence herbicide? Let us hear from you in the comments!