Soaking rains bring much needed water to our desert environment, including plants. Rainwater is especially beneficial to plant material as rainwater is less alkaline than our irrigation water. While rain is a positive thing for our plants and irrigation water bills, it also helps weeds grow. For effective weed control in your yard, manual removal is the easiest way to get rid of a small number of weeds. To control weeds over a large area, herbicides are the most efficient tools available. There are two categories of herbicides for weed control: Pre-emergent and Post-emergent.
Pre-emergent herbicides are designed to prevent seeds from germinating in the soil. They are most effective when applied during the rainy season. In Arizona, that means either before the summer monsoon in June & July and from October through January to take advantage of the winter rains. A timely application of pre-emergent can greatly reduce the number of weeds that germinate since it inhibits the weeds’ roots and does not allow them to grow.
Post-emergent for winter and spring weeds:
Post-emergent herbicides kill weeds that have germinated and are visible in the landscape. To kill weeds in winter months, you need to use a herbicide containing Diquat.
Spectracide products, which contain Diquat, are available for personal use at most home improvement stores or nurseries.
Post-emergent for summer weeds:
Spring and summer are the best times to use Roundup concentrate. Be careful not to spray weed killer on plants or turf as the weed chemical is absorbed by the leaves and travels through the plant. These products cannot differentiate between plants and weeds. Additionally, this type of weed killer does not instantly kill the plant. If you spray the weed and then remove it, any remaining roots may not have time to absorb the weed control spray.
*Product label design and prices may vary. These products are Environmental Protection Agency (EPA) approved and have been deemed safe and reliable. No license is needed to apply most herbicides on your own property. DLC trains and maintains a crew of applicators to safely transport and apply these herbicides in your common areas. Our spray applicators are Licensed Pest Applicators by the State of Arizona Office of Pest Management. When dealing with any chemical, make sure to read the label and follow instructions carefully.