Using a combined “Weed and Feed” product offers the convenience of applying both herbicide and fertilizer in a single step. This dual-action approach aims to nourish the turf while simultaneously eliminating or preventing weed intrusion. Correct application is paramount, especially in Florida where the subtropical climate and dominant warm-season turfgrasses create unique challenges. Standard national advice for lawn care often proves ineffective or harmful when applied to Florida landscapes.
Understanding Weed and Feed in the Florida Climate
Florida’s climate presents a significant challenge for using combination lawn products, primarily due to high heat and humidity. Most Florida lawns consist of warm-season grasses such as St. Augustinegrass, Zoysiagrass, and Bahiagrass. These grasses have different tolerance levels to herbicides compared to northern varieties. The “weed” component, typically a broadleaf herbicide, can severely injure these sensitive turf types if applied incorrectly.
Warm-season grasses enter a period of reduced growth, known as semi-dormancy, during the mild Florida winter. Applying the “feed” component (fertilizer) too early while the turf is still dormant can promote weed growth instead of grass growth, as weeds often become active first. Furthermore, the sandy nature of Florida’s soil means nutrients can rapidly leach out. This runoff, particularly of nitrogen and phosphorus, poses a serious environmental risk, contributing to water pollution and harmful algal blooms.
The Critical Timing: When to Apply in Florida
Timing the application of a Weed and Feed product is the most important factor for success in Florida, affecting both lawn health and weed control effectiveness. The initial spring application must be delayed until the grass is actively growing. This ensures the turf is ready to absorb the fertilizer and withstand the herbicide. A reliable indicator for this active growth phase is when the soil temperature consistently reaches between 55°F and 65°F at a depth of two to four inches.
This typically translates to a calendar window of late February to early March for Central and South Florida, and around March 1 for North Florida. Waiting until the lawn has required mowing at least twice in the spring is a practical way to confirm the turf has fully emerged from its winter slowdown. Applying the product too early, while the grass is still sluggish, can result in chemical burn and injury to the turf.
Weed control timing is often divided into two strategies: pre-emergent and post-emergent. A pre-emergent herbicide is designed to form a barrier and prevent weed seeds from germinating. It must be applied before the soil hits the critical temperature threshold that triggers weed seed activity. The post-emergent herbicide within a Weed and Feed eliminates weeds that have already sprouted and is most effective when applied to young, actively growing weeds.
Peak summer is generally a period to avoid using Weed and Feed due to the combination of high temperatures and fertilizer stress. Herbicides become less selective and are more likely to injure the turf when air temperatures consistently exceed 90°F. The intense heat combined with rapid nutrient release can scorch the grass. This high-stress period aligns with the state’s rainy season, which also introduces legal restrictions on fertilizer use.
Florida Fertilizer Regulations and Application Method
The use of combination products in Florida is heavily regulated, primarily due to the environmental impact of nutrient runoff during the rainy season. Many local governments enforce ordinances that prohibit the application of fertilizers containing nitrogen and phosphorus, the two main components of the “feed” part of the product. This ban generally runs from June 1 through September 30, coinciding with the state’s wettest months.
These regulations are designed to protect water quality by preventing excess nutrients from washing into storm drains and local water bodies during heavy rainfall. Homeowners must check their specific local ordinances, as some jurisdictions, particularly in South Florida, may extend the ban period. Applying a product containing nitrogen or phosphorus during a restricted period is a violation of these local laws.
When timing and local regulations allow for application, proper technique is necessary for the product to be effective and safe. Granular Weed and Feed products must be applied to slightly damp grass. This allows the herbicide granules to stick to the weed leaves, where they are absorbed. The application should be done with a properly calibrated spreader, walking at a consistent pace to ensure uniform coverage and prevent scorching caused by over-application.
After application, keep the lawn dry for 24 to 48 hours to give the herbicide time to work on the weeds. Once the waiting period is over, the product should be watered in thoroughly to activate the fertilizer and any pre-emergent components in the soil. Florida law also mandates a non-application buffer zone, often 10 feet, around water bodies. Any granules that land on impervious surfaces like driveways or sidewalks must be swept back onto the lawn to prevent them from washing into the storm drain system.