Our pre-emergent lawn fertilization round begins March 13th and will be available through April 15th depending on the weather. Sign up today for the most important fertilizer application of the year.
Pre-emergent lawn weed control helps prevent broadleaf weeds before they are established. While labeled a weed killer, more simply it stops the seeds of common Colorado lawn weeds from being established.
Pre-emergent is applied in early spring before the soil temperature reaches around 55°. By stopping weeds before they emerge, your lawn will have fewer weeds and less need for spot spraying of a contact weed killer. We’ve seen the results over and over again.
What happens is, as the weather becomes warmer, it signals grass and weeds to come out of dormancy, start gathering nutrients, and to initiate photosynthesis. If broadleaf weeds become established, they basically out-compete and crowd out grasses. The pre-emergent turns this around and allows grass to establish and use nutrients in the soil by slowing or preventing broadleaf weeds from growing.
However, there is an important role for you. Pre-emergent, in its granular form, is activated by water which is one of the issues for timing a proper application. While it is water-activated in its granular form, the timing of the application is best done before most folks have their sprinklers turned on. An unactivated pre-emergent will gradually lose its potency if exposed to sun and mild spring days.
So if your lawn service comes by to apply pre-emergent weed control, and your sprinklers aren’t on (and there’s no rain), it’s important to hand-water your lawn to activate the granules.
Liquid pre-emergent is available, too, with the advantage of quicker entrance into the soil zone. However, it’s more costly, and will temporarily stain the lawn with a yellowish color until it has leached into the soil.