Every June 1, Palm Beach County homeowners and property managers face the same question: how do you keep a lawn looking sharp for four solid months without nitrogen or phosphorus? For too long, the default answer has been “just wait it out.” That’s a mistake. The blackout isn’t a pause button. It’s the part of the year where soil-first lawns genuinely separate themselves from synthetic-program lawns, and the opportunity is to build a healthier soil profile, harden the turf against summer stress, and reduce your dependence on rescue chemistry for the rest of the year.

This guide walks through the exact blackout-compliant inputs we use at Granuly, why each one works specifically for South Florida turf, and how to build a monthly schedule that gets a lawn into October stronger than it went into June. Whether you maintain a single residence in Palm Beach Gardens or manage a coastal HOA portfolio from Tequesta to Boca Raton, the framework is the same.

The blackout rules (and the local nuances most people miss)

Palm Beach County’s Florida-Friendly Fertilizer Use Ordinance prohibits the application of any fertilizer containing nitrogen (N) or phosphorus (P) to turf or landscape from June 1 through September 30. The reasoning is environmental: our wet season dumps an enormous volume of rain in a short window, and N and P that get washed into storm drains end up fueling algal blooms in the Lake Worth Lagoon, the Loxahatchee River, the Intracoastal, and ultimately the reef tract offshore. The blue-green algae events that show up in the C-51 and C-44 canals during heavy summers are a useful reminder that this isn’t abstract policy. It’s about water you can see from your dock.

A few specifics worth knowing:

• The ban applies to any product where the first two numbers of the N-P-K analysis aren’t zero. A 15-0-15 fertilizer is out. A 0-0-22 with micros is fine.
• A 10-foot fertilizer-free buffer applies near any water body. Three feet is allowed if a deflector shield is used on the spreader.
• New sod has a limited 30-to-60-day exception for establishment. Document the install date and product used in case Code Enforcement asks.
• Applications are also prohibited during a National Weather Service Flood, Tropical Storm, or Hurricane Watch or Warning, or if two inches of rain or more is forecast in 24 hours.
• Commercial applicators must hold Green Industries Best Management Practices (GI-BMP) certification and a Limited Commercial Fertilizer Applicator license through FDACS. Ask any company you’re paying for this before they touch your lawn.

The municipal stricter-rule trap

This is where most of the compliance headaches happen, and it’s worth flagging early because the same address can fall under two different sets of rules depending on which side of a town line it sits on:

For property managers running a portfolio across multiple cities in northern Palm Beach County, this is the single most common compliance error we see. A landscape contractor finishes a job in West Palm Beach on October 5 (legal, county ordinance expired September 30) and rolls the same truck and the same fertilizer to a property inside the Village of North Palm Beach (illegal until November 1). When in doubt, always verify the specific municipality before any application after September 30.

The mental shift: feed the soil, not the lawn

A standard synthetic-N program is essentially life support delivered through the leaf. Push some quick-release nitrogen, the grass gets greener for three weeks, push more. Pull that input away (which is exactly what the blackout does), and a lawn that has been living application-to-application starts to fade fast.

Soil-first programs don’t fade because they aren’t dependent on the input you just removed. The grass is being supported by a functioning soil food web that breaks down organic matter, makes existing minerals plant-available, and helps roots access water and nutrients on their own. The blackout months are arguably the best four months of the year to build that soil, because soil biology is most active when soils are warm, moist, and undisturbed by chemical herbicides and fungicides. South Florida’s June through September gives you all three at once.

That’s the philosophy. Here’s the regimen.

Nutrition: potassium and micronutrients

You can’t use N or P during the blackout, but you can lean heavily on the two nutrients that do the most useful work in a Florida summer: potassium and iron.

Potassium (K), the summer hero

Potassium is the most underappreciated nutrient in Florida lawn care, and it’s the one nutrient you can lean on heavily during the blackout because it’s perfectly legal to apply. K does almost everything you want a summer feed to do without any runoff risk:

• Thickens cell walls. This makes turf more resistant to the fungal diseases (large patch, gray leaf spot, take-all root rot) that spike during the wet season.
• Improves drought tolerance and water-use efficiency. Critical during the surprisingly dry stretches between summer storms.
• Strengthens the root system. Particularly important for shallow-rooted Floratam St. Augustine after a stress event.
• Boosts heat and salt tolerance. Both are realities in coastal Palm Beach County, especially anywhere east of US-1.

The most common blackout-legal sources are sulfate of potash (0-0-50), muriate of potash (0-0-60), and soluble potassium products designed for foliar feeding. We favor sulfate of potash for residential turf because it carries a lower salt index than muriate and adds a small amount of sulfur, which is helpful in our typically alkaline coastal soils.

Application timing matters more than you’d think. Light, frequent K feedings (every three to four weeks at low rates) outperform a single heavy slug. Florida sand has almost no cation exchange capacity, a fancy way of saying it can’t hold onto nutrients between rain events. Spoon-feed, don’t blast.

Micronutrients, especially iron

If you can’t apply nitrogen and you’re still expected to deliver a green lawn, iron is your closest friend. Iron drives chlorophyll production directly, which means it greens the grass without forcing top growth. That’s a win twice over: the lawn looks better, and you’re not mowing every five days.

A chelated iron (typically Fe-EDDHA for our high-pH coastal soils, or Fe-DTPA for slightly less alkaline conditions) applied as a foliar or as a granular at 2 to 4 oz per 1,000 square feet will visibly deepen color within 48 to 72 hours. Foliar iron sulfate is cheaper but lasts only 2 to 4 weeks and doesn’t work nearly as well on alkaline soils where the iron oxidizes quickly. On a coastal property, the chelated form is almost always worth the price difference.

Manganese, zinc, copper, and boron are also blackout-legal and worth including in trace amounts, especially for properties that have been on heavy synthetic programs for years and are likely deficient. A standard micronutrient package (often labeled “minors” or “trace pak”) usually contains all of these in balanced ratios.

A soil test is the right starting point if a property has never had one. The UF/IFAS Extension office at Mounts Botanical Garden offers affordable soil testing, typically around $20, with results in about two weeks. The report tells you exactly which micros you’re short on and whether your pH is going to interfere with iron uptake regardless of how much you apply. Without that baseline, every fertilizer decision is a guess.

Soil: surfactants, humic acid, and biostimulants

Nutrition is half the equation. The other half is the soil itself: whether it can absorb water, hold onto nutrients, and support the microbiology that drives a self-sustaining lawn. These three inputs are the workhorses of the soil side of a blackout program.

Wetting agents (soil surfactants)

Wetting agents sound boring until you understand what they’re doing. Palm Beach County soils are predominantly sand, often with a hydrophobic (water-repellent) layer that develops as organic matter coats the sand grains. The visible symptom is “localized dry spots,” patches of lawn that brown out in spite of regular irrigation. Water hits the surface, can’t penetrate, and runs off.

A monthly soil surfactant application breaks the hydrophobic layer and pulls water down into the root zone. In practice, properties on a wetting agent program use roughly 20 to 30 percent less irrigation water for the same turf moisture level. During the rainy season, the same product helps move standing surface water down through the profile rather than pooling on top, which directly reduces disease pressure.

Major commercial brands (Aquatrols Revolution, Hydretain, yucca-based products like Penterra) are all blackout-compliant. They contain no N or P. Read the label and confirm.

Humic and fulvic acids

Humic substances are the most concentrated form of stable organic matter you can apply to a lawn. Florida sand is among the worst soils in the country for organic matter retention, which is why a fresh load of compost seems to “disappear” within a season under our heat and microbial activity.

Humic acid is the large-molecule, longer-residual portion. It binds to sand particles and improves cation exchange capacity, meaning soil can finally hold onto nutrients rather than letting them leach past the root zone with the next storm. Fulvic acid is the smaller-molecule, faster-acting portion: a natural chelator that shuttles minerals across the root membrane. A potassium application made with fulvic acid is meaningfully more efficient than the same K applied alone.

A liquid humic-and-fulvic blend applied at label rate every four to six weeks during the blackout is one of the highest-return inputs you can make. Results aren’t always visible above ground in the first month. They’re happening in the root zone and show up as resilience six months from now, when the lawn next door is yellowing and yours isn’t.

Sea kelp (seaweed extract)

Ascophyllum nodosum, the cold-water kelp used in most commercial seaweed extracts, is one of the most studied biostimulants in turf science. It contains naturally occurring cytokinins and auxins (plant hormones that signal root and shoot development), a broad spectrum of micronutrients, and alginates that help the plant tolerate heat, drought, and salt stress.

For Palm Beach County specifically, the salt stress angle matters more than people realize. Anywhere within a few miles of the coast deals with salt-laden air, and any property irrigating off a well that pulls from the surficial aquifer may have measurable sodium in the water. Coastal properties on Singer Island, Jupiter Island, and the barrier islands often show salt stress symptoms that get misdiagnosed as nutrient deficiency. A monthly kelp application visibly improves how the turf handles these stresses, and we pair it with humic and fulvic acid in the same tank mix routinely. They’re complementary, and the combined cost per application is reasonable.

Pressure: natural pest and disease management

The blackout months are also the peak pressure window for the insects and diseases that damage South Florida turf. The temptation is to reach for whatever synthetic product knocks down the symptom fastest. The problem is that most synthetic pyrethroids and broad-spectrum fungicides also wipe out the predatory insects and soil microbiology you’ve been carefully building. Two steps forward, two steps back.

Natural insect control

Four insects do most of the damage to South Florida lawns in summer: southern chinch bug (the worst offender in Floratam St. Augustine), tropical sod webworm, fall armyworm, and mole crickets (more of an issue in Bahia and Bermuda). Effective natural alternatives:

• Beneficial nematodes. Steinernema and Heterorhabditis species are microscopic parasites that hunt soil-dwelling larvae of armyworms, sod webworms, mole crickets, and chinch bugs. Applied as a drench and watered in. One application gives roughly six to eight weeks of protection if soil moisture stays adequate, which during our rainy season is automatic.
• Cedarwood and rosemary essential oil products. Brands like Cedarcide and Wondercide are highly effective against chinch bugs and surface-feeding caterpillars and break down quickly without residual toxicity to bees, butterflies, or beneficial soil insects.
• Neem oil. As a foliar spray, neem suppresses a broad range of insects by disrupting their molting cycle. It’s also mildly antifungal, a useful bonus during wet weather.
• Bacillus thuringiensis (Bt). Specifically the kurstaki strain, Bt is a soil bacterium that produces a protein lethal to caterpillars but harmless to almost everything else. The gold standard for sod webworm and armyworm control.
• Diatomaceous earth (food grade). Works well for ant control around the perimeter but should not be broadcast across the whole lawn, since it’s also lethal to pollinators and beneficial insects on contact. Spot use only.

Natural disease control

South Florida summers are a fungal incubator: warm, wet, humid, with the grass canopy staying damp for days at a time. The three diseases that show up most predictably are large patch (formerly brown patch), gray leaf spot in St. Augustine, and take-all root rot.

The good news: most fungal disease in Florida is driven by stress (over-irrigation, low potassium, poor drainage, mower scalping), and addressing the cause is far more effective than chasing the symptom. The potassium, humic, and kelp pillars above are already fungicidal in effect because they produce healthier, more resilient turf. When direct intervention is needed:

• Bacillus subtilis biofungicides. Serenade and Companion colonize the leaf surface and outcompete pathogenic fungi. Allowed during the blackout, and work well as a preventative every three to four weeks during peak disease season.
• Bacillus amyloliquefaciens products. Similar mechanism, particularly effective against large patch.
• Potassium bicarbonate. Kaligreen and MilStop directly disrupt fungal cell walls and conveniently double as a potassium source.
• Hydrogen dioxide and peroxyacetic acid. Products like ZeroTol are useful as a knockdown when there’s active disease and you need to stop it immediately.
• Cornmeal top-dress. Feeds a Trichoderma species that suppresses several soil-borne fungi. Slower and more agronomic, but inexpensive and effective on a longer timeline.

What we generally avoid even though it’s technically “natural”: copper-based fungicides. They work, but copper accumulates in soil and at chronic exposure suppresses earthworms and microbial activity, which is the opposite of what we’re trying to build over a four-month program.

A monthly blackout schedule

This is the framework we run on most Palm Beach County properties, adjusted for grass type, sun exposure, soil test results, and irrigation setup. It’s a starting point, not a prescription.

Mowing should stay on the high end of the range for the grass type during these months: 4 to 4.5 inches for Floratam, 2.5 to 3 inches for Empire Zoysia, 1.5 to 2 inches for Celebration Bermuda. Higher mowing means deeper roots, which means more drought and disease resilience. Don’t scalp during summer. It’s the single most common avoidable mistake we see.

Common mistakes we still see every summer

A few things that consistently sabotage otherwise good blackout programs:

• Over-irrigating. During the wet season, most Palm Beach County lawns need zero supplemental irrigation. If a controller is still running June through September on the same schedule it ran in April, the property is inviting fungal disease and washing inputs straight past the root zone. Set the controller to “Off” by default and only manually water during dry spells.
• Mowing too short. Scalped grass is stressed grass, and stressed grass is disease-vulnerable grass. Florida summer is the wrong time to “make the lawn look manicured” by dropping the deck.
• Applying anything in the 24 hours before a forecast tropical system. Wasted product and a direct code violation. The ordinance language is explicit about heavy-rain forecasts.
• Ignoring the 10-foot waterway buffer. Property managers near the Intracoastal, canals, and HOA ponds get cited for this constantly. Use a deflector shield and walk the perimeter before you start.
• Treating the lawn like it’s still on a synthetic program “just without the nitrogen.” A real blackout program isn’t a stripped-down version of a year-round synthetic regimen. It’s an entirely different approach (soil-first, biology-forward, K and micros centered) that happens to be the law for four months and happens to produce better long-term outcomes.
• Skipping the soil test. You can’t build a real soil program without knowing what the soil is starting with. Mounts Botanical Garden Extension turns soil tests around in about two weeks for around $20. There’s no excuse not to have one on file.

The Granuly approach

Our programs are built on a few simple principles: feed the soil, not just the blade. Use the blackout months to build long-term resilience instead of treating them as a forced pause. Stay in lockstep with the specific municipality’s ordinance, including the stricter October-31 jurisdictions that catch out-of-county contractors every fall. And start every property with a soil test, every time.

A lawn that gets a real blackout program (not the “skip a few applications and hope” approach) comes out of September with deeper root mass, higher organic matter, better soil moisture retention, and far less accumulated disease pressure than its synthetic-program neighbors. The first post-blackout fertilizer application in October produces a visibly stronger response because the soil can finally hold and exchange the nutrients you’re applying. That compound effect is the whole point. The gap between soil-first lawns and synthetic-program lawns widens every year you stay on the regimen.

If you’d like us to build a custom blackout-period program around your specific property, soil profile, and municipality (with the right product selection, the right cadence, and the compliance work handled for you), reach out for an on-site assessment. We work with homeowners, HOAs, and commercial property managers across Palm Beach County and the Treasure Coast.

The right inputs, in the right amounts, at the right times. That’s the whole job.

FAQ

Brandon Seymour

Founder, Granuly

Brandon started Granuly with a clear goal: get lawns and landscapes to thrive with fewer chemical inputs. By combining organic, low-toxicity treatments with proactive cultural practices, he designs each program around plant biology, soil chemistry, and products he’d use in his own yard. Brandon holds multiple licenses with the Florida Department of Agriculture and Consumer Services, is Florida-Friendly certified, and is a proud member of the Palm Beach Chapter of the Florida Nursery, Growers and Landscape Association.