The dual-action product known as “weed and feed” combines a selective herbicide to control broadleaf weeds with a fertilizer to nourish the turfgrass. This two-in-one approach offers efficiency, but its effectiveness relies on precise application timing, especially concerning water. The challenge is balancing the needs of the two components: the herbicide requires time to stick and absorb into the weeds, while the fertilizer needs water to dissolve and reach the soil. Understanding the correct sequence of preparation, application, and post-treatment waiting maximizes the benefits of this product.
Preparing the Lawn for Optimal Treatment
Preparing the lawn correctly ensures the herbicide component makes proper contact with the target weeds. It is recommended to mow the lawn one to two days before application. This timing allows the weed leaves to be exposed and ensures the granular particles settle directly onto the weed’s foliage instead of being blocked by tall grass blades.
The most important step before application is lightly moistening the weed leaves, accomplished by a brief watering or applying the product when morning dew is present. This moisture helps the herbicide granules adhere to the broadleaf weed surface. Although moist soil benefits the fertilizer component, the immediate goal is ensuring the weed-killing granules stick.
Application should be done with a calibrated spreader, ensuring even coverage across the lawn to prevent over-fertilization or missed weeds. Since the product works on the weeds’ leaves, it is best applied to a dry lawn surface after the leaves have been dampened. This preparation sets the stage for the absorption period, allowing the selective post-emergent herbicide to begin its work.
The Critical Waiting Period
The most common question concerns the waiting period before watering, which is consistently a minimum of 24 to 72 hours. This delay is based on the mechanism of how the herbicide kills the weeds. The granular herbicide particles must remain undisturbed on the broadleaf weed leaves long enough for the active ingredients to dissolve and be absorbed.
These post-emergent herbicides, often containing compounds like 2,4-D or Dicamba, are absorbed through the foliage and translocated throughout the weed’s vascular system. If the lawn is watered or if heavy rain occurs too soon, the water washes the granules off the leaf surface before absorption is complete. This significantly reduces weed control effectiveness and results in wasted product.
The herbicide component must be prioritized during this initial window, even though the fertilizer needs water to dissolve and reach the grass roots. The wait time ensures the weed-killing agent has sufficient contact time to penetrate the weed’s waxy leaf cuticle. Waiting for the full recommended period, typically 24 to 48 hours, ensures the herbicide is fully integrated into the weed’s system before the fertilizer is activated.
Post-Treatment Activity and Watering Schedule
Once the critical waiting period of 24 to 72 hours has passed, the first watering can be initiated to complete the treatment process. This irrigation dissolves the remaining fertilizer granules and washes the nutrients deep into the soil profile for root absorption. A thorough watering, aiming for about a half-inch of water, is recommended to ensure the fertilizer is fully activated and to prevent potential fertilizer burn.
It is important to limit foot traffic and keep pets off the treated area during the waiting period to prevent disturbing the granules. The first mowing after application should be postponed for two to four days, or at least 24 to 48 hours after the first watering. Mowing too early risks cutting off treated weed leaves before the herbicide has fully moved into the root system, reducing the treatment’s effectiveness.
An unexpected light rain during the waiting period may not be a disaster, but heavy rain warrants a contingency plan, as it will likely wash away the product. If a significant downpour occurs, the product label should be consulted, as reapplication might be necessary after a suitable recovery period. Following these steps ensures the dual-action product delivers both weed control and the intended boost of fertilizer.