The product known as “weed and feed” combines a broadleaf herbicide with a lawn fertilizer, offering a dual treatment in a single application. This combination nourishes the turf while simultaneously eliminating or preventing common weeds. Achieving maximum benefit depends entirely on precise timing, which must be calibrated to the specific regional climate and the type of grass being treated. In Texas, applying the product at the wrong time can be ineffective or even damaging to the lawn due to varied growing seasons.
Knowing Your Texas Lawn: Grass Types and Climate Zones
The majority of Texas lawns use warm-season grasses, which thrive in summer heat but enter dormancy during cooler winter months. The most common varieties are St. Augustinegrass, Zoysiagrass, and Bermudagrass, each having different tolerances for heat and shade. Understanding your specific grass type is the first step in creating an effective treatment schedule.
Texas is often divided into climate zones (North, Central, and South/Coastal), which dictates the length of the growing season. North Texas has a shorter season with later spring green-up compared to the milder Gulf Coast and South Texas regions. This regional variation means application dates must be adjusted, sometimes by a month or more, to align with local soil conditions rather than calendar dates. The timing is directly linked to local temperatures and the grass’s active growth phase.
Critical Spring Timing for Pre-Emergent Weed Control
The most important application of the year is the first one in the spring, focusing primarily on pre-emergent weed control. Pre-emergent herbicides must be applied before weed seeds germinate to create a protective barrier in the soil. The primary target is annual grassy weeds like crabgrass, which sprout when the soil temperature consistently reaches 55°F.
Monitoring the soil temperature, not the air temperature, is the most reliable method for determining this application window. This window typically opens in late February or early March in South Texas and along the Gulf Coast. In North Texas, it usually occurs later, closer to late March or early April. Applying the pre-emergent too early allows the chemical barrier to break down before all weed seeds have germinated.
The fertilizer component prevents an ultra-early application. Warm-season grasses should be actively growing, or fully “greened-up,” before receiving a heavy dose of nitrogen fertilizer. Applying the product while the turf is dormant means nutrients are largely unused and may instead promote weed growth or contribute to nutrient runoff. It is recommended to wait until the lawn has required mowing two or three times before the first fertilizer application.
Summer and Fall Schedules for Feeding and Post-Emergent Treatment
After the initial spring treatment, a mid-season application during the summer helps sustain the turf through the peak growth period. Warm-season grasses benefit from repeat feedings, spaced approximately 6 to 8 weeks apart to maintain a steady nutrient supply. Summer feeding supports the lawn’s density and resilience against heat and drought stress.
Avoid broad application of “weed and feed” products during the hottest summer months when air temperatures are consistently above 85 to 90°F. The herbicide component can cause temporary burning or stress to the turf when applied under extreme heat. For active weeds that appear during the summer, spot treatments with a liquid post-emergent herbicide are a safer alternative.
The final crucial application is the fall feeding, often called the “winterizer,” which focuses on strengthening the root system. This treatment should contain a higher percentage of potassium to help the grass recover from summer stress and prepare for winter dormancy. Timing must occur about 4 to 6 weeks before the first expected frost date. Applying nitrogen too late encourages tender new leaf growth susceptible to cold damage, so a final cut-off date of early to mid-October is recommended for Central and North Texas lawns.
Essential Preparation and Post-Application Steps
Proper preparation and post-application care are essential for the success of granular “weed and feed” products. Before application, the lawn should be mowed at the normal height a day or two prior to treatment. For the post-emergent herbicide to be effective against existing broadleaf weeds, the grass blades must be damp or covered in dew so the granules stick to the foliage.
After the granules have been spread uniformly, delay watering for a specific period, typically 24 to 72 hours. This waiting time allows the herbicide component to be absorbed by the weed leaves. Watering too soon will wash the herbicide off the weeds before it can take effect, rendering the weed control useless.
Once the waiting period is complete, the lawn must be watered with about a half-inch of irrigation to activate the fertilizer and pre-emergent components. This watering dissolves the remaining granules, moving the nutrients and the pre-emergent barrier into the soil. Always consult the product label for specific temperature restrictions, as application during excessive heat can lead to turf burn.