Landscaping
Landscape and turf IPM field guide: pests, disease, and weeds
Identify before you spray, scout on a schedule, fix the conditions that favor the pest, and treat with the least-risk option that works, by the label, every time.
Direct answer
Integrated pest management is a decision process, not a spray schedule. You identify the problem, monitor it, set an action threshold, prevent it with healthy turf and cultural practices first, then treat with the least-risk effective option and evaluate the result. Local cooperative extension guidance and the pesticide label govern every rate and timing.
Key takeaways
- Integrated pest management runs six steps in order: identify, monitor, set an action threshold, prevent, control least-risk first, then evaluate.
- White grub action threshold is about 10 grubs per square foot in healthy turf, dropping to roughly 4 to 6 on stressed turf.
- Apply crabgrass pre-emergent before the 2-inch soil temperature holds around 55 degrees F, watching a local soil-temperature tracker, not the calendar.
- The pesticide label is legally binding under FIFRA; the rate, sites, PPE, and re-entry interval are all violations to exceed.
- Rotate the IRAC, FRAC, or HRAC mode-of-action group number printed on the label, not the brand name, to manage resistance.
What IPM is, and why it beats spraying on a calendar
Integrated pest management is a way of deciding when and how to act on a pest, not a product and not a spray date on a calendar. You watch the property, figure out what is actually wrong, decide whether the damage is bad enough to treat at all, and when it is, you reach for the option that fixes it with the least collateral cost. Spraying is the last tool you pick up, not the first.
The opposite approach is the blanket calendar spray: same insecticide, same fungicide, same weed-and-feed, same week every year whether the property needs it or not. It feels like service. It is mostly waste. You pay for product the lawn did not need, you kill the beneficial insects that were holding the real pest in check, and you train the survivors to shrug off your chemistry, which is how a product that worked for ten years suddenly stops working.
IPM costs more thinking and less product. A crew that scouts and identifies treats fewer acres, uses cheaper cultural fixes more often, and gets called back less. The recurring side of this work, the mowing and feeding and the scouting cadence, lives in the commercial maintenance program guide. This guide is the pest, disease, and weed half of the same job.
What are the steps of integrated pest management?
IPM runs in a set order, and the order is the whole point. Most cooperative extension and EPA material lays it out as six moves, and skipping the early ones is what turns a program back into spray-and-pray.
Identify the problem correctly first, because the wrong ID sends you after the wrong target. Monitor and scout so you know how widespread it is and whether it is getting worse. Set an action threshold, the amount of pest or damage that justifies treating. Prevent the problem with cultural practices and resistant grass before it starts. Choose a control only when the threshold is crossed, working from least-risk to most-risk: cultural, then mechanical, then biological, then chemical. Then evaluate what you did, because the follow-up tells you whether it worked and what to change next time.
The early steps are free or cheap and the late steps cost money and risk. A program that spends its effort on identification, monitoring, and prevention treats less and treats better. The one most crews skip is the last one. Nobody writes down whether the application actually worked, so the same wrong call gets made again next season.
Why does correct identification come first?
You cannot treat what you have misdiagnosed, and most of the wasted applications in this trade start with a bad ID. A brown patch in the lawn is not automatically a fungus. It could be grubs, chinch bugs, drought, dull mower blades, a buried slab, dog urine, fertilizer burn, or a fungal disease, and the fix for each one is different. Spray a fungicide on grub damage and you have spent money, hit the beneficials, and the grubs keep eating.
Sort the cause into one of two buckets first: living or not living. A biotic problem (insect, disease, weed) usually spreads over time and often shows a pattern at the edges, like a ring or an advancing front, or you can find the organism itself. An abiotic problem (drought, compaction, salt, chemical, mechanical) tends to match a feature of the site: it follows the cart path, the dry spot the irrigation misses, the strip along the road where the plow piled salt, or the exact shape of where the dog goes.
When you are not sure, get it identified before you spray. A county cooperative extension office or a land-grant university diagnostic lab will identify an insect, culture a disease, or read a weed for a small fee, and that ID is worth more than a guess and a tank of product. Bag a fresh sample from the edge of the damage, not the dead center, where the organism has already moved on.
The three pest groups, and the disorders that fake them
Landscape problems sort into three living groups plus a fourth that is not alive at all. Insects feed on roots, crowns, or foliage. Diseases are mostly fungal in turf, driven by moisture and temperature. Weeds are plants growing where you do not want them, competing for light, water, and nutrients.
The fourth group is abiotic disorders, and it is the one that gets misdiagnosed as a pest more than any other. Drought, compaction, scalping, salt, dog urine, fertilizer or herbicide burn, buried debris, and poor drainage all produce dead or off-color turf that looks like an insect or a disease at a glance. The tell is the pattern. Abiotic damage matches the site, holds a straight line or a geometric shape, and does not spread the way a living pest does. Living damage spreads, follows the biology of an organism, and you can usually find the culprit if you look.
Get the group right and the rest of the program follows. Get it wrong and every step after it is aimed at the wrong target.
Turf insects: grubs, chinch bugs, billbugs, and caterpillars
Turf insects do two kinds of damage, and the damage tells you where to look. Root feeders work below ground and the turf wilts, thins, and pulls up. Surface and leaf feeders chew the crowns and blades and the damage spreads outward from a focus.
White grubs are the big one. They are the larvae of beetles, Japanese beetle and the masked chafers being the usual offenders, and they eat turf roots in late summer. The classic sign is irregular brown patches in late August or September that do not green up with water, and turf so rootless it peels back like a loose piece of carpet. Birds, skunks, and raccoons tearing up the lawn at night are feeding on the grubs and are a sign in themselves.
Chinch bugs suck the sap out of sunny, dry turf and leave expanding yellow-to-brown patches that people blame on drought. Billbug larvae hollow out stems and the grass breaks off easily at the crown, leaving behind a sawdust-like frass. Sod webworm and fall armyworm are caterpillars that chew the blades, armyworm in fast-moving fronts that can strip a field in days. Confirm any of them before you treat, because each has a different threshold and a different window.
| Insect | What it damages | Field sign |
|---|---|---|
| White grubs | Roots, late summer | Irregular brown patches, turf rolls up like carpet, animals digging |
| Chinch bugs | Crowns, sunny dry turf | Expanding yellow-brown patches in heat, mistaken for drought |
| Billbugs | Stems and crowns | Stems break at the crown, sawdust frass, grass pulls free easily |
| Sod webworm | Leaf blades | Notched, ragged blades, small brown patches, green pellets in thatch |
| Fall armyworm | Leaf blades | Fast-spreading front, can strip turf in days, active early morning |
How do you get rid of grubs in a lawn?
First confirm you have enough grubs to matter. Cut three sides of a one-square-foot flap of sod a few inches deep, peel it back, and count the white C-shaped larvae in the root zone. A commonly cited action threshold is about 10 grubs per square foot in healthy turf, lower, around 4 to 6, on stressed turf or where birds and skunks are already digging. Your local extension sets the number for your region and grass, so treat the count as a starting point, not a law.
Timing splits the chemistry into two strategies, and using the wrong one wastes the application. Preventive products, the ones with chlorantraniliprole or a neonicotinoid like imidacloprid, go down before or around egg hatch and sit in the soil to kill the young grubs as they start feeding. Across much of the country that means late spring through midsummer, with chlorantraniliprole applied earlier than the neonicotinoids because it moves more slowly to the root zone. Curative products like trichlorfon kill grubs already present and feeding, and they work best in late summer and early fall while the grubs are small and near the surface. They act fast and break down fast, so they give no future protection. Confirm the timing and rate against the label and your extension before you mix.
Biological options exist and have their place. Milky spore and beneficial nematodes are covered in the biological controls section.
Turf diseases: the fungi, and the conditions that switch them on
Most turf disease is fungal, and a fungus needs three things at once to flare: a susceptible grass, the pathogen present, and the right environment, which for turf almost always means moisture and a temperature window. Change the environment and you have changed the disease, which is why the first move on disease is cultural, not a fungicide.
Leaf wetness is the lever you can actually pull. Most foliar fungi need many hours of continuous moisture on the blade to infect, so watering in the early morning instead of the evening, improving airflow, and knocking the dew off high-value turf all cut infection without a drop of fungicide. Reading the disease backward to its conditions tells you what to fix.
The table below pairs the common diseases with the conditions that drive them and the cultural lever that fights them. A fungicide, when it is warranted, works far better as a preventive ahead of the conditions than as a rescue after the turf is already collapsing, and the product label and your extension set the timing and the rate.
| Disease | Conditions that trigger it | First cultural fix |
|---|---|---|
| Brown patch | Hot humid nights in the 70s, long leaf wetness, cool-season turf | Water in the morning, improve airflow, hold back nitrogen in heat |
| Dollar spot | Heavy dew, warm days, low nitrogen, drought stress | Keep adequate nitrogen, remove dew, water deeply not often |
| Large patch | Cool wet soil in spring and fall, warm-season turf | Reduce thatch, improve drainage, avoid fall nitrogen on warm-season grass |
| Pythium blight | Hot humid weather, low spots, poor drainage, lush growth | Fix drainage, cut nitrogen, increase airflow, avoid mowing when wet |
| Summer patch | High soil temperature, compacted or wet soil, bluegrass roots | Relieve compaction, raise mowing height, manage soil pH and nitrogen |
| Snow mold | Long snow cover or cold wet matted turf | Mow late into fall, avoid late heavy nitrogen, do not pile snow |
Ornamental and tree pests: shrubs and trees on the property
A landscape contract is more than turf, and the beds and trees come with their own pest list. The same IPM order applies: identify, scout, threshold, prevent, then treat the least-risk way.
Aphids cluster on new growth, suck sap, and leave a sticky honeydew that grows black sooty mold. A hard stream of water or the lady beetles and lacewings already on site often handle a light infestation without a spray. Scale insects look like bumps glued to stems and leaves and are easy to miss until the plant declines, with a dormant-oil window in late winter that is the cleanest time to hit them. Spider mites flare in hot dry dust, stipple the leaves bronze, and spin fine webbing, and a broad insecticide makes them worse by killing their predators.
Borers are the ones that kill, because by the time you see the entry holes and frass the larvae are already inside the trunk or stem, so the play is prevention through plant vigor and correct species placement rather than rescue. Bagworms build the little spindle-shaped bags that hang off arborvitae and junipers, and there is a narrow window in early summer to treat the young larvae before the bags harden and the season is over. Shrub and tree diseases follow the same moisture-and-temperature logic as turf disease, so leaf spots, blights, and cankers respond first to sanitation, airflow, and correct watering.
Weeds, and what the weed tells you about the turf
A weed is a symptom as much as a problem. The species that shows up is reading your site back to you, so identifying the weed by category tells you both how to control it and what the turf is missing. Sort weeds three ways: leaf type, life cycle, and season.
Broadleaf weeds like dandelion, clover, and plantain have wide leaves and a netted vein pattern. Grassy weeds like crabgrass, goosegrass, and annual bluegrass look like grass and hide in the lawn until they do not. Sedges look grass-like but have triangular stems and love wet ground. Life cycle splits them into annuals that come back from seed each year and perennials that persist from roots, and the season splits them into summer annuals like crabgrass that germinate in spring heat and winter annuals like annual bluegrass that germinate in fall.
The category points at the cause. Heavy clover often means low nitrogen. Prostrate knotweed marks compaction. Nutsedge and moss flag drainage and shade. Crabgrass thriving means the turf is thin enough to let light hit the soil. Match the grass to the site, covered in the turfgrass selection guide, and keep a dense stand, and you have removed the opening most weeds need.
What is the difference between pre-emergent and post-emergent herbicide?
Pre-emergent and post-emergent are two strategies aimed at two different moments in a weed's life. A pre-emergent goes down before the weed seed germinates and forms a barrier in the top layer of soil that stops the seedling as it emerges. It does nothing to a weed you can already see. A post-emergent is sprayed on a weed that is already up and growing and kills the living plant.
Pre-emergent is all about timing, and crabgrass is the case everyone learns on. The window is set by soil temperature, not the calendar: get the product down before the 2-inch soil temperature holds at about 55 degrees F, because that is where crabgrass starts to germinate, with most of it coming up as soil reaches the 60s. Miss the window and the barrier goes down behind the weed, where it does no good. Soil temperature varies by year and region, so watch a local soil-temperature tracker, not last year's date.
Post-emergents split into selective, which kill the target while sparing the desired grass, and non-selective like glyphosate, which kill anything green and are for spot work, renovation, and hardscape cracks, never broadcast over a lawn you want to keep. Read the label for the turf species it is safe on, because the wrong selective herbicide will take the lawn with the weed.
Healthy turf is the best pest control you have
A dense, vigorous stand of the right grass outcompetes most weeds, hides minor insect feeding, and recovers from disease on its own. Most pest problems are a symptom of weak turf, and the cheapest pest control on the property is the mowing, feeding, and watering that keeps the stand thick. This is the prevention step of IPM doing its job before any pest gets a foothold.
Four practices carry most of the load. Mow at the high end of the range for the species and never take more than a third of the blade at a cut, because scalping shocks the plant and opens the canopy to weeds. Water deeply and infrequently to push roots down, and do it in the morning so the blades dry fast and disease gets less leaf-wetness time. Feed to the grass's need, not by habit, because too much nitrogen feeds disease and lush weak growth while too little invites clover and thin spots. Relieve compaction and manage thatch so water and air reach the roots.
The grass itself is a control. Choosing a species and cultivar suited to the climate, the shade, the traffic, and the water you can give it, the subject of the turfgrass selection guide, decides how hard the rest of the program has to work. The right grass in the right place shrugs off problems the wrong grass would die from.
What is an action threshold?
An action threshold is the level of a pest or its damage at which treating is justified, and below it you do nothing but keep watching. Seeing a pest is not a reason to spray. Finding enough of it to cause damage you cannot accept is. The threshold is what separates a real program from a reflex.
Thresholds come in two flavors. A numeric threshold is a count, like grubs per square foot or chinch bugs per square foot from a scouting check. An aesthetic threshold is a judgment about how much visible damage a given property will tolerate, and it is lower on a corporate entrance than on a back slope nobody sees. The contract and the client's expectations set the aesthetic number; extension research sets the numeric one.
The reason the threshold matters is money and resistance. Treat below threshold and you spend on product the property did not need and you select for resistance in a population that was never going to cause damage. Treat at threshold and the application is paying for itself by stopping real loss. Scout, count, compare to the threshold, then decide. That is the whole discipline.
Monitoring and scouting: how you find the problem early
Scouting is the routine inspection that feeds every other decision, and without it the thresholds and the timing are guesses. Walk the property on a regular cadence, look at the turf and the beds deliberately, and check the spots that always go first: the south-facing slope that dries out, the low wet corner, the shaded bed, the high-traffic strip.
Use the tricks that pull the pest into the open. The soap flush brings up surface insects: mix a couple tablespoons of dish soap in a gallon of water, drench a square yard at the edge of a suspect patch, and chinch bugs, billbugs, sod webworm, and armyworm crawl to the surface within a few minutes. For grubs, cut and peel a square-foot flap and count. For disease, look for the pattern, the ring or front, and check whether the damage spreads day to day or holds still like an abiotic spot.
Map what you find. Note the hot spots that recur season after season, because those are where you scout first and treat earliest, and the record turns scattered observations into a pattern you can act on. The maintenance program guide covers folding this cadence into the regular service visit so it actually happens instead of getting skipped when the crew is behind.
Cultural controls: fix the conditions, not just the pest
Cultural control means changing the way you manage the site so the conditions stop favoring the pest. It is the first control you reach for because it is cheap, it lasts, and it does not breed resistance or kill beneficials. Most of the time it is the same good agronomy that grows healthy turf, aimed now at a specific problem.
Mowing height and frequency, irrigation timing and depth, fertility, aeration, thatch management, and the choice of a resistant variety are the levers. Raise the mowing height and you shade out crabgrass and deepen the roots. Switch irrigation to the early morning and you cut the leaf-wetness hours that brown patch needs. Drop a spring nitrogen push on a disease-prone warm-season lawn and you stop feeding large patch. Core-aerate a compacted athletic field and you take away the stress that let summer patch in.
The move that pays the longest is planting resistance up front. Many turf cultivars and tree and shrub varieties are bred or selected for tolerance to the diseases and insects common in a region, and choosing them, often noted in the variety description and extension trials, removes the problem before it can start instead of fighting it every year.
Mechanical and physical controls
Mechanical control is physically removing or blocking the pest, and on a small enough scale it beats a spray on cost and risk. Hand-pulling a young weed before it seeds takes seconds and removes a plant that would otherwise drop thousands of seeds into next year's lawn. The rule is to get it before it flowers, because one season's seed is several seasons of weeding.
Pruning out the problem works on woody plants. Cut out a borer-infested limb, a cankered branch, or a bagworm-loaded section and you have removed the pest and its next generation with it, and the cuts go in a bag off the property, not in the mulch pile where the disease overwinters. Sanitation, clearing diseased clippings and leaf litter, removes the spores that would reinfect.
Traps and barriers round it out. Pheromone traps monitor an insect's flight and time the treatment window, though they catch too few to control a population on their own. Mulch and landscape fabric block weed germination in beds. None of this scales to acres of turf, but for a defined infestation it is often the cleanest fix on the list.
Biological controls: beneficials, milky spore, and nematodes
Biological control uses living organisms against the pest, and the first form of it is free: the beneficial insects already on the property. Lady beetles, lacewings, predatory mites, ground beetles, and parasitic wasps hold aphids, mites, and small caterpillars in check until a broad-spectrum insecticide kills them off and lets the pest rebound worse than before. Conserving those natural enemies, by spraying narrowly and only at threshold, is the highest-return biological practice there is.
For grubs, two products get applied directly. Milky spore is a bacterium, Bacillus popilliae, that infects Japanese beetle grubs specifically. It is slow, taking a few seasons of cold-climate buildup to establish, and it does not touch the other grub species, but once established it can persist in the soil for years. Beneficial nematodes are microscopic worms, Heterorhabditis bacteriophora being the species that hunts scarab grubs, that you water into moist soil to kill grubs within weeks. They need moisture going down and after, and they have a short shelf life, so handle and apply them by the supplier's directions.
Biologicals are not a faster or stronger chemical. They are slower, narrower, and more conditional, and they fit best as part of a program rather than as a single rescue. Where they fit, they fit cleanly, with no resistance pressure and no harm to the beneficials you are trying to keep.
Chemical control and the treatment window
Chemical control is the last option in the order, not the first, and it is the right call when the threshold is crossed and the lower-risk tools will not get there in time. Used that way it is a tool. Used as the whole program it is the thing that wastes money, kills beneficials, and breeds resistance.
Pick the product for the specific target, the narrowest one that does the job, and put it down in its window. Timing splits into preventive and curative for both insects and disease. A preventive insecticide goes down before or at egg hatch and sits in the soil for the young insect, the grub strategy above. A curative goes after the active feeding stage. A preventive fungicide goes on ahead of the disease conditions, before the outbreak, where it protects far better and at a lower total cost than a curative trying to stop a disease already through the stand. Miss the window and even the right product underperforms.
Every one of these calls, the product, the rate, the target, the timing, comes off the label and your local extension's recommendation for your region and grass, not off a rule of thumb. The next sections cover the legal and mechanical parts that make the application correct: the label, the calibration, the resistance rotation, and the environmental buffers.
The pesticide label is the law
The pesticide label is a legal document, and applying a product in any way the label does not allow is a violation of federal law under FIFRA, the Federal Insecticide, Fungicide, and Rodenticide Act. This is not a guideline you weigh against the schedule. The rate, the sites you may treat, the target pests, the personal protective equipment, the re-entry interval, the storage, and the disposal are all on the label, and the label controls all of them.
Read it before you mix, every product, every time, because labels change. The rate on the label is the maximum that is legal and the amount that works, so more is both illegal and a waste that drives resistance. The restricted-entry interval, the REI, is the time after application before anyone goes back on the treated area without the label's PPE, and when you tank-mix two products with different REIs you follow the longer one. The PPE section tells you what to wear, and it is there because the product can hurt the person holding the wand.
Most commercial application requires a license. States run certification and licensing through their department of agriculture, split into private and commercial applicator categories, and some products are restricted-use and may be applied only by or under a certified applicator. Keep records of what you applied, where, when, the rate, the target, and who applied it. Federal law requires records for restricted-use products and most states require more, and the record is what protects you if anyone asks.
Calibration: the rate only counts if the equipment is right
The label rate is meaningless if the sprayer or spreader is not calibrated, because the machine, not your intention, decides how much product hits the ground. An uncalibrated sprayer either over-applies, which is illegal, wasteful, and a resistance driver, or under-applies, which fails to control the pest and looks like a product problem when it is an equipment problem.
Calibration ties output to area. For a sprayer, you measure how much volume the rig puts down over a known area at a fixed speed and pressure, then adjust so the tank delivers the label's gallons per 1000 square feet or per acre. A common backpack target is on the order of 1 to 1.5 gallons per 1000 square feet, but the label spray volume and your nozzle govern it. Walking speed, pressure, and nozzle wear all move the number, so hold a steady pace and check the rig regularly. A common guidance is to calibrate at first use and after roughly every fourth application, and any time you change a nozzle, a speed, or a product.
Spreaders need the same treatment. Set the gate, weigh out enough granular product for a measured area, apply it, and confirm what came out matches the rate, because a spreader setting off a generic chart can be well off for your specific machine and product.
Resistance management: rotate the mode of action
Use the same chemistry on the same pest generation after generation and you breed a population that survives it. The few naturally resistant individuals are the ones left to reproduce, and within a few seasons the product that worked stops working. Resistance management is how you keep your chemistry effective, and the rule is to rotate the mode of action, not just the brand name.
Mode of action is grouped and numbered so you can tell which products are actually different. The Insecticide Resistance Action Committee assigns IRAC group numbers, the Fungicide Resistance Action Committee assigns FRAC numbers, and the Herbicide Resistance Action Committee assigns HRAC numbers, and the group code is printed on the label. Two products with different brand names but the same group number are the same mode of action to the pest, and rotating between them buys you nothing.
Rotate across group numbers, not products. The practical guidance is to alternate among several different group codes for a given pest or disease target over a season, and to avoid hitting successive generations of the same pest with the same group. Reading the group number off the label and keeping a simple log of what group you used where is what makes a rotation real instead of a guess.
Pollinator and environmental protection
A pesticide that drifts off target or hits the wrong place stops being pest control and becomes a liability, so stewardship is part of doing the application correctly, not an add-on. The label carries the legal requirements for this too, including bee-protection and buffer language on many products.
Protect pollinators by keeping product off blooming plants when bees are working them. Do not spray flowering weeds in the turf or flowering ornamentals during the day, mow off the flowers first or treat in the evening when foraging has dropped, and follow any bee-hazard statement on the label. Many of the insecticides that control turf and ornamental pests are also toxic to bees, so the timing and the target are how you avoid the harm.
Protect water and the air around the site. Leave the buffer the label specifies near ponds, streams, wells, and storm drains, because what runs off the turf ends up downstream. Spray in low wind to keep drift on your property and off the neighbor's, the cars, and the surface water, and use the larger droplet and lower pressure that keep the spray where you aimed it. The point is simple: the product belongs on the target and nowhere else.
Matching the program to the site
The same IPM order applies everywhere, but the aesthetic threshold and the priorities shift with the property, and pricing the program means knowing which is which.
A corporate campus or a data-center grounds contract is judged from the road and from the lobby glass, so the visible turf and the entrance beds carry a low aesthetic threshold and get the closest scouting, while the back acreage and the detention basin tolerate more. The high-visibility zones justify preventive disease and weed work; the low-visibility zones can ride on thresholds and spot treatment. An athletic field is judged on playability and safety, so grub damage that makes the surface peel and the footing fail crosses the threshold faster than the same damage on an ornamental lawn. An HOA or a retail strip lives and dies on curb appeal, which means weeds in the parking-lot islands and the entrance read as neglect long before they hurt anything.
Set the thresholds zone by zone in the scope, scout the high-value zones first and most often, and spend the prevention budget where the property is actually seen. That is how an IPM program stays both effective and profitable instead of treating the whole site to the standard of its most visible corner.
What to document
An application nobody recorded is an application you cannot defend, repeat, or learn from. The record is what tells you next season whether the call worked, what protects you if the state or a client asks, and what turns this year's scouting into a pattern. At a minimum, log the problem, what type it was, the threshold or trigger that justified acting, and the first response you chose.
Beyond the decision, capture the application itself: the product and its IRAC, FRAC, or HRAC group, the rate, the target, the location and area, the date and conditions, the REI, and who applied it under what license. The group number in the log is what makes the resistance rotation real, and the rate and area are what prove the application was on-label.
| Problem | Type | Threshold or trigger | First response |
|---|---|---|---|
| Brown patches, late summer, turf pulls up | Insect (white grubs) | About 10 grubs/sq ft in healthy turf, or animals digging | Confirm count, treat preventive or curative by season, per label |
| Spreading patches in humid heat | Disease (brown patch) | Active spread plus high-value, low-tolerance zone | Morning watering, airflow, hold nitrogen; preventive fungicide if warranted |
| Grassy weed in thinning lawn | Weed (crabgrass) | History of crabgrass, thin canopy | Pre-emergent before soil holds 55 degrees F; thicken the stand |
| Yellow-brown patch in sunny dry turf | Insect (chinch bug) | Soap-flush count over extension threshold | Spot-treat at threshold, raise mowing, deep watering |
| Off-color strip along the road | Abiotic (salt or compaction) | Pattern matches site feature, does not spread | Flush salt, aerate, no pesticide |
Common mistakes
- Spraying before identifying the problem, so the application is aimed at the wrong target.
- Calendar spraying the whole property on a fixed date whether it needs it or not.
- Treating a brown patch as a disease when it is grubs, drought, salt, or dog urine.
- Ignoring the cultural cause and spraying the symptom, so the problem comes right back.
- Putting crabgrass pre-emergent down after soil has passed 55 degrees F, behind the germination.
- Applying over the label rate, off-label sites, or without the required PPE and REI.
- Running an uncalibrated sprayer or spreader, so the real rate is anyone's guess.
- Rotating brand names instead of IRAC, FRAC, or HRAC group numbers, which is no rotation at all.
- Spraying blooming plants while bees are foraging, or skipping the water buffer.
- Applying without a license where one is required, or keeping no record of what went down.
Field checklist
Want this checklist to run itself on every job — with photo proof and a signed record crews can hand the customer? That's FieldOS.
Standards and references
The framework for IPM comes from the land-grant cooperative extension system and the EPA, which lay out the same decision order: identify and monitor, set thresholds, prevent, control with the least-risk effective option, and evaluate. Your state's cooperative extension and its diagnostic lab are the working reference for thresholds, disease and insect identification, and the products and timing recommended for your region and grass. Their guidance is local in a way no national rule of thumb can be, and the thresholds and timings in this guide are starting points to confirm against it.
The pesticide label is the legal authority on every application, enforced under FIFRA, the federal pesticide law, with the EPA registering products and your state department of agriculture handling applicator certification and licensing and the restricted-use rules. The label, not this guide, sets the rate, the sites, the PPE, the re-entry interval, and the record-keeping, and where a label and a habit disagree, the label wins.
For resistance management, the mode-of-action group codes come from the Insecticide Resistance Action Committee (IRAC), the Fungicide Resistance Action Committee (FRAC), and the Herbicide Resistance Action Committee (HRAC), printed on the label so you can rotate across true modes of action. Treat all of these as the controlling sources and hedge any number here to the label and your extension before you act on it.
Units and terms
IPM carries its own vocabulary, and the same idea shows up under a few names across labels, extension bulletins, and a scope of work.
Pest counts run per square foot for soil insects like grubs and chinch bugs, and spray and granular rates run per 1000 square feet or per acre, the two forms most turf labels use. Soil temperature for pre-emergent timing is read at the 2-inch depth. Keep the threshold, the rate, and the timing in the units the label and your extension use, and convert carefully when a source mixes them.
- IPM
- Integrated pest management, the decision process of identify, monitor, threshold, prevent, control, and evaluate
- Action threshold
- The pest count or damage level that justifies treating; below it, you monitor and do not treat
- Biotic vs abiotic
- A living cause (insect, disease, weed) versus a non-living one (drought, compaction, salt, chemical)
- Pre-emergent / post-emergent
- An herbicide that stops weed seed before it germinates versus one that kills a weed already growing
- Preventive / curative
- An insecticide or fungicide applied ahead of the pest or disease versus one applied after it is active
- REI
- Restricted-entry interval, the label time after application before re-entry without the required PPE
- Mode of action / RAC group
- How a product kills, grouped by IRAC, FRAC, or HRAC number on the label, the basis for rotation
- Cultural control
- Changing mowing, watering, fertility, or variety so site conditions no longer favor the pest
FAQ
What is integrated pest management?
Integrated pest management is a way of deciding how to handle a pest by identifying it, scouting it, and treating only when damage crosses a threshold, using the least-risk effective control. It treats spraying as the last option after cultural, mechanical, and biological tools, and it follows local extension guidance and the label.
What is the difference between pre-emergent and post-emergent herbicide?
A pre-emergent stops weed seeds before they germinate by forming a barrier in the soil, so it must go down before the weed appears. A post-emergent kills a weed already growing. Selective post-emergents spare the lawn; non-selective ones like glyphosate kill anything green and are for spot work only.
How do you get rid of grubs in a lawn?
First confirm the count by peeling a square-foot of sod, since about 10 grubs per square foot in healthy turf is a common action threshold. Then treat by season: a preventive product before egg hatch in late spring to summer, or a curative like trichlorfon in late summer. Confirm rate and timing on the label.
What is an action threshold?
An action threshold is the level of a pest or damage at which treating is justified, set by a count or by how much visible damage a property will tolerate. Below it, you keep scouting and do not treat. It exists so you spend product only on real damage, which saves money and slows resistance.
How many grubs per square foot before you treat?
A commonly cited threshold is about 10 grubs per square foot in healthy turf, dropping to roughly 4 to 6 on stressed turf or where skunks and birds are already digging. The number varies with grass type, turf health, and region, so confirm the threshold with your local cooperative extension before you treat.
Is it better to spray on a calendar or scout first?
Scouting first wins almost every time. Calendar spraying treats problems that may not exist, wastes product, kills the beneficial insects holding pests in check, and breeds resistance. Scouting tells you what is actually there and whether it crosses the threshold, so you treat less, treat the right target, and get called back less.
What do I do if a fungicide or insecticide stops working?
A product that quit usually means resistance from repeating the same mode of action. Check the IRAC or FRAC group number on the label and rotate to a different group, not just a different brand. Confirm your identification and timing too, and lean on cultural fixes so the chemistry is not carrying the whole load.
When should I apply crabgrass pre-emergent?
Apply crabgrass pre-emergent before the 2-inch soil temperature holds around 55 degrees F, since that is where crabgrass starts to germinate. Watch a local soil-temperature tracker rather than the calendar, because the date shifts by year and region. Once weeds are up, switch to a labeled post-emergent instead.
Do I need a license to apply pesticides to a lawn?
Commercial application usually requires a license. States run certification through their department of agriculture, split into private and commercial categories, and some restricted-use products may be applied only by or under a certified applicator. Check your state's rules, and keep records of every application, which federal law requires for restricted-use products.
Why is healthy turf the best pest control?
A dense, vigorous stand of the right grass outcompetes weeds, hides minor insect feeding, and recovers from disease on its own, so most pest problems are really a symptom of weak turf. Proper mowing height, deep infrequent morning watering, sensible fertility, and relieving compaction prevent more pests than any spray, at lower cost and no resistance risk.