“Weed and feed” products offer a convenient, dual-purpose approach to lawn maintenance, combining a complete fertilizer with an herbicide in a single formulation. These products are designed to simultaneously deliver essential nutrients to the turfgrass while controlling broadleaf weeds like dandelions and clover. They are available in both liquid and granular forms. For maximum effectiveness, the sequence of lawn care tasks, especially mowing, is an important factor. Proper timing ensures the product works as intended, maximizing the benefit to your lawn.
Mowing Before Application: The Essential Rule
The general rule for applying granular weed and feed is to mow the lawn a couple of days before the treatment, allowing a window of 2 to 4 days between cutting and application. This timing is designed to reduce mechanical stress on the turfgrass, which can temporarily inhibit its ability to absorb nutrients and recover properly. Mowing too closely to the application limits the surface area on the weeds available to absorb the herbicide. Cut the grass at its normal, recommended height, rather than scalping it. Allowing a brief recovery period of 48 to 72 hours ensures that the grass is ready to receive the fertilizer and the weeds have sufficient leaf matter exposed for the herbicide to adhere.
Why Weeds Need Leaf Surface Contact
The efficacy of the weed-killing component relies on the herbicide making direct contact with and being absorbed by the weed’s foliage. Most post-emergent herbicides are systemic, meaning they must be absorbed through the leaf surface and then translocated throughout the plant, down to the roots, to achieve complete elimination. If the weeds are cut immediately before treatment, there is insufficient leaf surface area for the chemical to stick to and penetrate. Granular weed and feed products are specifically formulated to adhere to the moist, broad leaves of weeds. The granules contain the herbicide, which dissolves slightly upon contact with the damp leaf surface and must remain on the leaf long enough to be absorbed. For liquid spray products, the herbicide is sprayed directly onto the foliage, often requiring a dry leaf surface for optimal absorption. In contrast, granular products require a slightly damp surface, usually from morning dew or light watering, so the granules can stick to the weed leaves.
Post-Application Mowing and Watering Guidelines
After the weed and feed has been applied, it is important to wait before mowing again to ensure the herbicide is fully absorbed by the weeds. It is recommended to avoid mowing for a period of 2 to 4 days following the application. Mowing too early would remove the leaves coated with the herbicide, cutting off the chemical before it has had adequate time to translocate to the weed’s roots. Granular weed and feed often requires a specific watering schedule to activate both the herbicide and the fertilizer. A light watering or morning dew is needed at the time of application to help the granules stick to the leaves. Avoid heavy watering for 24 to 72 hours following the application. This delay allows the systemic herbicide time to be absorbed by the weeds before the fertilizer component is washed into the soil. Once the waiting period has passed, a thorough watering is beneficial as it moves the fertilizer into the root zone of the turfgrass. Always check the product label for the precise waiting period before watering, as formulas can vary.