“Weed and Feed” is a dual-action product combining granular fertilizer with an herbicide, designed to simplify lawn care by tackling two tasks in a single application. Applying it in Florida presents unique challenges due to the state’s subtropical climate, diverse turfgrass species, and stringent environmental protection laws. The product’s effectiveness relies on precise timing, which must align with the grass’s active growth cycle and local regulations intended to prevent nutrient runoff into waterways.
Florida’s Grass Types and Growth Cycles
The correct timing for any lawn product is dictated by the specific turfgrass species and its life cycle. Florida lawns are overwhelmingly composed of warm-season grasses that thrive in high temperatures, including St. Augustinegrass, Zoysiagrass, and Bahiagrass. These grasses exhibit their most vigorous growth when air temperatures are consistently high, typically between 75 and 90 degrees Fahrenheit.
During Florida’s cooler winter months, these warm-season grasses enter a period of semi-dormancy, where growth slows significantly or stops entirely. Applying fertilizer during this dormant phase is ineffective and detrimental. Since the grass roots are not actively absorbing nutrients, the fertilizer sits unused on the soil surface. This makes it highly susceptible to being washed away by rain, contributing to environmental pollution. Weed and feed products should only be applied after the turf has fully emerged from dormancy and is actively growing.
Determining the Right Application Timing
The most reliable indicator for proper spring application timing in Florida is the soil temperature, which governs the grass’s emergence from dormancy. You should wait until the soil temperature, measured at a two-inch depth, consistently reaches 65 degrees Fahrenheit for several consecutive days before applying a granular fertilizer component. This threshold signals that the warm-season grass roots are sufficiently active to absorb and utilize the added nutrients.
The timing for the herbicide component of the product, however, is slightly different depending on the desired effect. For pre-emergent weed control, which targets summer annual weeds like crabgrass before they sprout, the ideal window is when soil temperatures reach a consistent 55 to 60 degrees Fahrenheit. This temperature coincides with the germination of these weed seeds, creating the perfect opportunity for the pre-emergent barrier to be established.
The conflict between optimal temperatures means using a combined weed and feed product can be problematic. Applying fertilizer too early risks nutrient runoff, but waiting until the grass is actively growing may be too late to stop early-germinating weeds. Therefore, the safest application window generally occurs in the late spring. This timing is after the threat of a late frost has passed and the grass has been mowed at least twice, indicating it is fully out of dormancy.
Navigating Florida’s Fertilizer Restrictions
Local ordinances govern lawn care timing due to Florida’s waterways. Over 100 cities and counties across the state have implemented strict fertilizer regulations to combat nutrient pollution, primarily targeting nitrogen and phosphorus. These nutrients fuel harmful algal blooms and degrade water quality in the state’s coastal and inland waters.
A major constraint is the “Rainy Season Ban,” which is enforced by many coastal and central Florida counties, typically running from June 1st through September 30th. During this period of heavy rainfall, the application of fertilizers containing nitrogen or phosphorus is prohibited because the high volume of water significantly increases the risk of runoff. Applying a standard weed and feed during this blackout period can result in fines, regardless of the turf’s growth cycle.
Further restrictions govern the nutrient content of the product itself, particularly phosphorus. Most Florida lawns already contain sufficient phosphorus, and its addition is legally restricted unless a soil test proves a deficiency. Many weed and feed products containing phosphorus are thus banned for general use. Additionally, year-round “fertilizer-free” buffer zones are mandated along the edges of water bodies, such as canals, ditches, ponds, and seawalls, often requiring a 10- to 20-foot application setback.
Step-by-Step Application Guide
Once timing and local restrictions are considered, the application requires precision. Begin by mowing the lawn to its normal recommended height two to four days before application. This ensures the granular product can easily reach the soil surface while also allowing weed leaves to grow slightly, maximizing the surface area available for herbicide absorption.
Before spreading the product, calibrate the spreader according to the manufacturer’s instructions for the specific product and spreader model. Uniform application is achieved by applying half the material in one direction across the lawn and the second half perpendicularly, creating a crosshatch pattern. Care must be taken to avoid spreading the granules onto sidewalks, driveways, or street surfaces. This material must be swept back onto the turf to prevent it from washing into storm drains.
Post-application steps depend on the specific herbicide in the product. If the product contains a pre-emergent herbicide, the lawn must be watered immediately after application to dissolve the granules and activate the chemical barrier in the soil. If it contains a post-emergent herbicide designed to kill existing weeds, a waiting period of 24 to 48 hours is necessary before watering to allow the chemical to absorb into the weed foliage. In either case, avoid mowing the lawn for at least two to three days after spreading the product to give the herbicide sufficient time to be effective.