Diagnose problems before you treat them
Integrated pest management as a sequence: prevent, scout, identify, set a threshold, act with the least-risk option, and check the result.
Start here Essentials
This module asks you to look before you act: walk the garden every week, name the problem, and start with the least risky fix. Everything marked Go deeper is optional on a first pass.
- Walk the garden one morning a week. Look at every crop, both sides of the leaves, and the base and soil. Log one row per crop in the problem log, including "no damage". The weekly walk.
- Check the water first. Push a finger into the soil 2 inches down before you blame a pest.
- Identify before you act. Use the symptom table, look for the confirming sign, and mark the identification provisional until a source or lab confirms it. Identify by symptom.
- Act with the least risk first: hand-pick, cover, prune or fence. A product comes last, and its label is the law. This course names no product. Products, labels and where to ask.
- Write down your help before you need it: your county extension office and the National Pesticide Information Center, 1-800-858-7378.
Minimum time: about 30 minutes for the first walk. Done when: your first scouting walk is logged.
1. Integrated pest management is an order of operations Understand
Something is eating the beans. The natural reaction is to find out what kills that kind of thing and use it. That reaction skips the step that decides whether anything works: knowing what the problem is. A spray chosen for slugs does nothing to an insect, and a fence does nothing to a fungus. Many of the "problems" a first-season gardener sees are not pests at all: a wilt from dry soil, a pale leaf from shade, a spot from a weather event.
Integrated pest management (IPM) is the approach extension services and the U.S. EPA teach for this. EPA describes it as a combination of common-sense practices that uses current information about pests' life cycles and their surroundings to manage damage at the least risk to people, property and the environment. It can include pesticides. It puts them last, and only after the earlier steps have been done.
The sequence
Convention EPA's IPM principles page lists four parts: set action thresholds, monitor and identify pests, prevent, and control. This course arranges them as six steps in the order a gardener meets them in a season:
| Step | What you do | What it prevents |
|---|---|---|
| 1. Prevent | Choose resistant varieties, rotate crop families, space for airflow, cover crops that need it, keep the garden clean, avoid excess nitrogen. | Problems that never need a decision. |
| 2. Scout | Walk the garden on a set day each week, look at every crop, both sides of leaves, and write down what you see. | Finding a problem only once it is large. |
| 3. Identify | Name the cause from the symptom and the culprit, confirm it with a source or a lab, and record how sure you are. | Treating the wrong thing. |
| 4. Decide on a threshold | Ask whether the damage, at this level, on this crop, at this stage, is worth acting on. | Acting on one insect that would not have mattered. |
| 5. Act, least risk first | Hand-pick, trap, cover, prune, fence. Only then consider a product, read its label, and follow it. | Broad treatments that harm allies and people. |
| 6. Check the result | Scout the same plants again the next week and record whether the action worked. | Repeating something that did not work. |
EPA's own wording is that broadcast spraying of non-specific pesticides is a last resort. The order matters because each step makes the next one smaller. Prevention means less to scout. Scouting early means smaller populations to identify. Correct identification often shows nothing needs doing.
Thresholds Go deeper
An action threshold is the level of a pest, or of the conditions that favor it, at which control is worth doing. EPA's point is that seeing a single pest does not mean action is needed. Thresholds depend on the crop and on what part of it you eat.
Convention Utah State University Extension's fact sheet on caterpillar pests of brassica vegetables gives an example. For head-forming crops such as cabbage, where caterpillars that get into the head are hard to reach, it gives a very low threshold: one caterpillar in 25 to 50 plants, or 10 percent of plants with at least one. It says crops that do not form heads tolerate higher numbers. The same publication's threshold for a leafy crop would be different, and the threshold for the same caterpillar on a crop you do not eat the leaves of would be different again.
Convention Tolerance is real. The UC Statewide IPM Program's aphid Pest Note says most established plants can tolerate aphid feeding and outgrow it. The University of Minnesota Extension's page on early blight says tomato plants can tolerate a lot of early blight without fewer fruit. A home gardener's threshold is also personal. Preference How much leaf loss you accept on kale you cook is your choice, not a rule.
This module teaches identification and the steps before any product. It never names a pesticide, an active ingredient to use, a rate or a mix. When a product is under consideration, the label on the product you hold, your extension office and the National Pesticide Information Center are the authorities, and Section 5 says how to reach them. An identification made from a photo on the internet, including one we help you make here, is provisional until a source you can check or a diagnostic lab confirms it.
2. Scout every week, and identify by symptom
Scouting is a planned, regular inspection of the garden to find problems early and record them. It is the cheapest control there is, and most of IPM depends on it.
The weekly walk
Convention UC IPM's aphid Pest Note says to check plants at least twice a week while they are growing fast, to look at the undersides of leaves, and to start on the upwind edge of the garden, where aphids are usually most common. Utah State's brassica sheet says to look for eggs and caterpillars on the undersides of leaves and on the innermost leaves, and to check at least 10 percent of the plants, inside the planting and on the edges. The University of Minnesota's squash vine borer page says a plant that is wilted in the morning needs a closer look, since wilting in strong afternoon sun alone is common.
From those, a weekly walk for a home garden:
- Same day, same time of day. Morning is best: wilting means more in the morning than in the afternoon heat.
- Every crop, every bed. Start on the upwind side. In a small garden, look at every plant; in a large one, at least one in ten, inside and at the edges.
- Turn leaves over. Undersides hold aphids, eggs and young caterpillars.
- Look at the base and the soil. Holes, sawdust-like material, chewed stems, tracks and slime trails are at ground level.
- Look at the allies. Lady beetles, lacewing eggs on stalks, swollen golden-brown aphids, white cocoons on a caterpillar (Section 3).
- Write it down in the problem log: date, crop, bed, what you saw, how many plants. Take a photo with something for scale.
- Check water before blaming a pest. Push a finger into the soil two inches down (Module 8). Dry soil wilts plants with no help.
Test it Some problems need a second, different visit. UC IPM's snail and slug Pest Note says they feed at night and on cloudy days and hide by day, so the check is at night or early morning with a flashlight. If damage appears overnight and no culprit is visible by day, a flashlight visit is the next step, not a guess.
Identify by symptom
The table lists the common beginner problems by what you see first. It names likely causes from the extension pages cited, and the sign that confirms or rules each one out. It is a starting point for identification, not a diagnosis. Frass, which several rows mention, is the excrement and chewed debris insects leave behind; its form and place are a clue to the culprit.
| What you see | Likely causes | How to confirm | Source |
|---|---|---|---|
| Irregular holes with smooth edges in leaves; small seedlings clipped | Slugs or snails; earwigs and caterpillars make similar holes | Silvery mucus trails are the best confirmation of slugs or snails. Check at night with a flashlight. No trails points elsewhere. | UC IPM Snails and Slugs |
| Ragged holes in cabbage-family leaves, green droppings, damage in heads | Imported cabbageworm, cabbage looper, diamondback moth caterpillars | Velvety green caterpillars with a faint yellow stripe (cabbageworm); yellow eggs singly on leaf undersides; white butterflies by day | UNH Imported Cabbageworm; Utah State brassica caterpillars |
| Chewing on many crops, entire rows of peas, beans, lettuce or beets gone | Rabbits | Whole plants or stretches of row gone, rather than holes in leaves; watch at dawn and dusk | University of Maryland Rabbits |
| Bites in tomatoes; plants eaten; a large burrow nearby | Groundhogs | Burrow entrance up to a foot wide with a soil mound; bite marks on tomatoes | University of Maryland Groundhogs |
| Wilting squash vine, worse each day, first in strong sun | Squash vine borer; also dry soil | Holes near the base packed with moist, greenish or orange sawdust-like frass. Check soil moisture first. | University of Minnesota Squash Vine Borers |
| Wilting of any crop in the afternoon, recovered by morning | Heat and dry soil | Soil dry two inches down; plants recover after watering or overnight | Module 8 |
| Brown spots with rings on lower tomato or potato leaves, yellow around them | Early blight | Spots up to 1/2 in with concentric rings, starting on older leaves near the ground and moving up | University of Minnesota Early Blight |
| White powder on squash, cucumber or pumpkin leaves | Powdery mildew | Talc-like growth on upper and lower surfaces, after pale yellow spots on older, shaded leaves | UConn Powdery Mildew of Cucurbits |
| Curled, yellowing leaves, sticky or black-coated | Aphids | Clusters on leaf undersides and new shoots; sticky honeydew, often with black sooty mold; ants tending them | UC IPM Aphids |
| Dark, leathery patch on the blossom end of tomato fruit | Blossom end rot, a disorder, not a pest | No insect or spot pattern on leaves; listed among tomato disorders | UC IPM Tomato; Nebraska G945 ties it to calcium transport in the plant |
| Missing seedlings where you sowed | Seed that did not germinate; seedlings eaten at ground level by slugs, earwigs or caterpillars; rabbits or birds | Dig gently where a seed should be. Check your germination test (Module 7). Night check for culprits. Look for trails or tracks. | Module 7; UC IPM Snails and Slugs; University of Maryland Rabbits |
Two things about that table. First, several symptoms have more than one cause, and the confirming sign is what separates them. Second, a symptom's cause can be a disorder: damage from a growing condition (water, temperature, nutrients, light) rather than from a living pest or pathogen. A disorder is not caught, spread or sprayed, and the fix is in the conditions. Blossom end rot is the best-known garden example.
Tools for the ones the table does not cover Go deeper
UC IPM's plant problem diagnostic tool narrows causes by plant type, plant, the part affected and the damage. Its page notes that a broad search gives many results and that the program cannot give individual solutions; it points users to their local extension office. Written for California, it is still a useful way to build a short list of candidates to confirm. Its Home and Landscape hub links the Pest Notes cited in this module.
3. Prevention, natural enemies and pollinators
EPA calls prevention the first line of pest control. In a home vegetable garden, five practices do most of the work.
Row covers, and when to take them off
A row cover is a lightweight, spun-bonded fabric laid over plants, or over hoops above them, that lets light, air and water through but keeps insects and some animals off. It works by keeping a pest from reaching the plant, so it has to go on before the pest arrives and be sealed at the edges.
Convention The University of New Hampshire's imported cabbageworm sheet calls spun-bonded floating row covers an effective barrier against egg-laying cabbageworm butterflies. Utah State says to put covers on just after planting or transplanting, over plants or over hoops, with the edges securely buried. Minnesota's squash vine borer page says to cover squash when vines begin to run (or, for bush types, in late June or early July, or when adults are first seen) and to anchor the edges so moths cannot get under.
Physical principle Some crops need insects to set fruit. Minnesota says to remove covers from squash once plants flower so bees can pollinate. Its page is about squash; the same reasoning applies to any crop whose fruit depends on insect pollination, which in this course's crop list means the squash family. Crops eaten for leaves or heads, such as cabbage, kale and lettuce, do not need pollination for the part you harvest, so their covers can stay on.
Convention Minnesota also warns not to cover a bed where cucurbits grew the year before, because borers that spent the winter in that soil emerge under the cover and are trapped in with the crop. That is a general lesson about covers: a cover keeps out what is outside, and keeps in what is already there. Rotation (Module 5) and covers work together.
Sanitation
Convention Minnesota's early blight page says the fungus survives the winter in infected debris and soil, and spreads by splashing soil onto lower leaves. Its sanitation advice: remove spotted leaves early (no more than one-third of a plant's leaves), bury or burn them, wash hands and clean tools after handling infected plants, and mulch to stop splash. The squash vine borer page says to pull and destroy plants killed by borers and clear crop debris. EPA's home composting page lists diseased and pest-infested plants among things to keep out of a home compost pile, since home piles often do not get hot enough. Module 12 covers end-of-season cleanup.
Resistant varieties Go deeper
Seed catalogs mark resistance with codes. The University of Illinois Extension's "Catalog Code" post explains common ones: for tomatoes, V and F for two wilt diseases, N for nematodes and TMV for tobacco mosaic virus; for cucumbers, CMV, PM (powdery mildew) and DM (downy mildew). Minnesota says early blight resistant tomatoes are often marked EB, and adds that resistance does not mean you will see no early blight: resistant plants tolerate it better. UConn's powdery mildew sheet lists resistant cucumber, squash and zucchini cultivars; its list may be dated, so check current catalogs for the code rather than a specific name. Minnesota's borer page notes that butternut squash is less susceptible than Hubbard and acorn types, and that cucumbers and melons are usually not attacked.
Spacing, sun and nitrogen
Physical principle Fungal diseases need moisture on leaves or high humidity. Minnesota gives early blight's conditions: spread is greatest in wet weather, heavy dew or humidity of 90 percent or more. UConn says powdery mildew does not need rain, develops at high humidity, and is heavier in shade and under overlapping leaves. Staking, spacing and weeding let leaves dry. Sun helps. Module 9 explained the last lever: UC IPM says high nitrogen favors aphids, and UConn lists avoiding excess fertilizer among powdery mildew controls.
Natural enemies Go deeper
UC IPM's Natural Enemies Gallery defines a natural enemy as an organism that kills, reduces the reproduction of, or otherwise reduces the numbers of another organism. It groups them as predators, parasitoids and pathogens. A parasitoid is an insect that lays eggs in or on another insect; the young feed on it and kill it.
Three a beginner can learn to recognize:
- Lacewings. The University of Maryland describes delicate green or brown adults with clear, finely veined wings longer than the body; eggs laid on the ends of long, fine stalks; and alligator-like larvae. Adults and larvae eat aphids, caterpillars, insect eggs and mites.
- Aphid mummies. UC IPM says an aphid parasitized by a tiny wasp turns crusty and golden brown, and that once mummies appear the aphid population may drop substantially within a week or two. Its list of common aphid predators includes lady beetles, lacewing larvae, soldier beetles and syrphid fly larvae.
- Cocoons on caterpillars. New Hampshire says whitish masses beside a dead cabbageworm are usually cocoons of a small wasp, which will hatch and go on to parasitize more caterpillars. Leave them.
Physical principle Allies need prey to stay. A garden scrubbed of every aphid has nothing for lacewings to eat. That is part of why thresholds exist. UC IPM also notes that ants tend aphids and protect them from predators, so ants on a plant are a clue worth logging.
Pollinators
Squash-family flowers need insect visits to set fruit, which is why Minnesota takes covers off at bloom. The University of Illinois Extension's guidance on protecting pollinators when using pesticides says to read the environmental hazards section of any label for bee warnings, to consider whether the plant or anything near it is flowering, to avoid highly bee-toxic products during bloom, to treat only problem areas, and to consider non-chemical options such as hand removal. Its broader point applies without any product: protecting pollinators is part of every decision in the garden, including when to take a row cover off.
4. Deer, rabbits, groundhogs and weeds
Animals are the problem a beginner most often underestimates, and the one most often solved by a barrier. The fence specifications below are published conventions from named extension services. The deer figures come from Arizona, and deer pressure, legal status and what works differ by region. Your extension office is the place to ask what works where you live.
| Animal | Barrier | Source and notes |
|---|---|---|
| Deer | A fence at least 8 ft tall of woven wire, high-tensile wire, UV-stabilized mesh or similar; deer can and will jump lower fences. Small areas may be protected by 4 to 6 ft fences. Or two low fences about 38 in apart. Or an electric fence with wires at 18 and 36 in. | University of Arizona Cooperative Extension, Yavapai County. Written for the Southwest; used here as a labelled example. The same sheet notes deer are a game species in Arizona and that methods from other states may not be legal there. |
| Cottontail rabbits | 2-ft chicken wire, the bottom secured to the ground or buried a few inches | University of Maryland Extension. Arizona's sheet gives 2-ft poultry wire buried at least 2 in for cottontails and 3-ft fence buried at least 6 in for jackrabbits. |
| Groundhogs | A strong 4-ft fence buried 12 in; an electric wire 4 to 5 in off the ground and the same distance outside the fence stops climbing | University of Maryland Extension |
| Squirrels and woodrats | They climb and dig; may require complete enclosure with poultry wire | University of Arizona (Southwest example) |
Ask the authority Before building any fence, check your lease, HOA rules or community garden rules, and local ordinances on fence height and electric fencing. Arizona's sheet adds that some people cannot use fences because of local ordinances. Arizona's sheet says to post warning signs on an electric fence; follow the charger maker's instructions. Wildlife laws vary by state: what you may do about a deer or a groundhog beyond fencing is a question for your state wildlife agency or extension office.
Repellents: Arizona's sheet notes that most deer repellents can be applied only to non-edible crops, the effect is temporary, and deer may get used to them. Home remedies such as hair and soap are, in its words, typically not as reliable as labeled repellents. Any repellent is a product with a label (Section 5).
Weeds
Convention Clemson HGIC's fact sheet on controlling weeds by cultivating and mulching says to remove weeds while young, since mature weeds take a lot of water and nutrients. It says hand-pulling suits small gardens and raised beds; hoeing must be shallow, because most vegetable roots are near the surface; and cultivating should move as little soil as possible to avoid bringing buried weed seed up. It calls mulch the easiest and most effective way to control annual weeds, at about 3 in of organic mulch free of weed seeds, and notes that perennial weeds such as yellow nutsedge can push through mulch and plastic. It says that for most gardens mulching and hand-weeding are enough and herbicides are not needed, and that few herbicides are safe on the range of crops in a garden. The weekly scouting walk is a good time to pull weeds while they are small.
5. Products, labels and where to ask
Sometimes the earlier steps are not enough and a gardener considers a product. This course does not recommend products, ingredients, rates or mixes. It teaches what to understand before using anything, and who to ask.
The label is the law
Convention The U.S. EPA's introduction to pesticide labels says pesticide labels, unlike most product labels, are legally enforceable, and that using a product in a way inconsistent with its labeling violates federal law. In EPA's words, "the label is the law." The label says which crops and sites the product may be used on, how much, how often, what protection to wear, how long to wait before harvest, and how to store and dispose of it. A product whose label does not list vegetables, or the crop in question, may not be used on it.
A pesticide, in this module, is any product used to kill, repel or control a pest: insects, slugs, fungi, weeds, animals. That includes products sold as organic or natural, and repellents.
Signal words
A signal word is the word on the front of a pesticide label that ranks its short-term toxicity. The National Pesticide Information Center's (NPIC) fact sheet on signal words explains:
| Signal word | What it means |
|---|---|
| CAUTION | Slightly toxic if eaten, absorbed through the skin or inhaled, or causes slight eye or skin irritation |
| WARNING | Moderately toxic by those routes, or moderate eye or skin irritation |
| DANGER | Highly toxic by at least one route, or corrosive, able to cause irreversible eye or skin damage |
| DANGER with POISON | Highly toxic products must also show POISON in red on the front panel |
Convention NPIC says signal words describe the acute (short-term) toxicity of the product. They do not describe long-term effects or effects on bees, fish or the environment; the label's other sections cover those. NPIC adds that every product still has the potential to poison, whatever its signal word, and it advises following all of the directions on the label.
Home remedies are pesticides too
Convention NPIC's page on pesticide home remedies says homemade mixtures usually have no label, so there is no direction on how much, where or how often, and no first aid or protective guidance. It says they may not have been tested to show they work, that too much of even a low-toxicity ingredient can be harmful, that concentrating or extracting ingredients can raise toxicity, and that preparing them in kitchen cookware can contaminate food. Its alternative is the IPM sequence: identify the pest, learn its biology, start with the least toxic methods, and ask your county extension office. UC IPM's slug Pest Note makes a related point from the other direction: crushed eggshells and coffee grounds have not been shown to stop slugs.
Ask the authority Community gardens often have rules. Plot 14's garden bans synthetic pesticides; others ban any pesticide, including organic and homemade ones, or require the coordinator's approval. Read the rules before using anything, and ask the coordinator in writing if they are unclear.
Storage
EPA's page on storing pesticides safely says: store them out of reach of children and pets, in a locked cabinet in a well-ventilated utility area or shed if possible; never with or near food, animal feed or medical supplies; always in the original container with the label; never transferred into drink bottles or other containers. It warns that child-resistant does not mean child-proof, says to keep containers away from places where flooding or leaks could reach drains or water, and advises buying only what you will soon use. If you cannot identify an old product, follow the disposal advice on EPA's page rather than using it.
Where to ask
- The label on the product you hold. It is the first authority and the legal one.
- The National Pesticide Information Center, at 1-800-858-7378, by email or by chat, for questions about a product, its risks, or an exposure. Its website showed a notice of reduced hours for 2026 on the day we checked; look there for current hours before calling. For a poisoning emergency, call poison control (1-800-222-1222 in the United States) or 911.
- Your county extension office, for identification and for what is labeled and allowed in your state. Find it through the Extension Foundation's directory of every state's extension institution.
- Master Gardener volunteers, trained through extension, often run help lines and clinics. The American Horticultural Society keeps a directory of Master Gardener programs by state and province.
Sending a sample to a diagnostic lab Go deeper
Many states' land-grant universities run a plant diagnostic lab, usually reached through the county extension office. The lab identifies diseases, insects and disorders from a physical sample. UMass Amherst's vegetable diagnostics page is a clear example of what labs ask for:
- Send two or three whole plants when you can, and whole plants up to about a foot tall with the root ball, because symptoms above ground can come from a problem below it.
- Remove loose soil and bag the roots so the soil stays off the leaves.
- Collect plants showing a range of symptoms; avoid dead or rotted ones.
- Wrap in newspaper or a plastic bag; do not add water or wet paper towels. Mail in a box.
- Fill in the lab's form completely, with a phone number and email.
UMass lists its own fees ($50 for a vegetable disease analysis at the time we checked). Fees, forms, accepted samples and who may submit differ by state. Some county offices accept samples and forward them; some identify insects for free. Ask your office before you dig anything up, and send the sample early in the week so it does not sit in a mailroom over a weekend.
We teach you to identify a problem, decide whether it needs action, try the least-risk options, and read a label you already hold. We do not tell you which product to use, at what rate, or whether a product is safe for your household, your pets or your shared plot. Those questions go to the label, NPIC, your extension office and, on a shared plot, the garden's rules. Keep any identification marked provisional in your problem log until a source you can check or a lab confirms it.
6. See it See it
Both examples use this course's fictional cases. Their frost dates and test results are invented.
Plot 14's bean seedlings. Dale Whitcomb and Ruth Asante sowed two rows of bush beans in their community plot in late May. A week after emergence, Ruth found about a third of the seedlings with ragged holes in the first leaves and several cut down to stubs. Dale searched the internet that evening, matched a photo, and decided it was slugs. He logged it that way, and Ruth suggested marking the identification provisional until they confirmed it. The garden bans synthetic pesticides, so whatever the cause, the answer had to fit that rule.
- Known: about a third of the seedlings in two rows damaged within a week; holes in leaves and stubs; no damage on the potatoes, onions or kale next to them; no slime trails on the two mornings they checked; the garden's no-synthetic-pesticide rule.
- Assumed: Dale's identification, slugs, from a matched photo. Provisional by the log's own rule.
- Open: what is actually chewing the beans, settled by the county extension diagnostic service from a sample; whether a trap or barrier on the shared plot is allowed, settled by the garden coordinator.
Confirming. UC IPM's slug Pest Note says silvery mucus trails are the best confirmation of slugs, and that earwigs and caterpillars make similar holes. No trails on two mornings was the first sign that the guess was weak. Following the same Pest Note, Dale went back after dark with a flashlight. He found no slugs, but found small, brown, fast-moving insects with pincers at the tail on several seedlings. He was not certain what they were. He called the county extension office, which told him to bring in two damaged seedlings with roots and soil in a bag, and a few of the insects in a sealed jar, on a weekday morning.
The result. The diagnostic service identified the insects as earwigs, consistent with the feeding, and found nothing on the seedlings to suggest disease. Dale's internet guess was wrong. The log row changed from "slugs, provisional, Dale (internet photo)" to "earwigs, confirmed, county extension diagnostic service." Whether the garden allows a trap on a shared plot is the coordinator's question, and they asked it in writing. Meanwhile they resowed the gaps, checked at night twice a week, and logged the count of damaged seedlings each time. By the third week, new damage had stopped on the larger plants, which the log records as the result.
What the sequence changed. Had they acted on the first guess, the slug barrier and night picking would have been aimed at an animal that was not there. The no-pesticide rule meant they would not have sprayed, but they would have lost a week. The confirmation cost an evening and a trip to the county office.
The Lindqvist deer. Nils and Karin Lindqvist's 20 × 30 ft garden had a 4-ft fence last year. Deer came over it nightly.
- Known: deer visit nightly; a 4-ft fence did not stop them; the garden is 600 sq ft, fully open on all sides.
- Assumed: that the Arizona sheet's statement that deer avoid jumping into small enclosed spaces does not apply to their garden, since it did not stop their deer at 4 ft (their assumption from one season).
- Open: what height or design their deer respect. Settled by their extension office's published guidance for their region and their own trial, logged in the wildlife sheet.
The only fencing source in this course is the University of Arizona's, written for the Southwest, which gives 8 ft or two low fences about 38 in apart. The Lindqvists treated that as a starting point, not an answer. Karin called their own county extension office, which pointed them to its state's deer fencing guidance. They checked their town's rules on fence height before choosing. They logged last year's failure, the new design and the date installed in the wildlife sheet, and will log every night they see damage.
- Integrated Pest Management Principles (U.S. EPA): the four parts of IPM, including thresholds and least-risk control first.
- Snails and Slugs (UC IPM Pest Notes): how to confirm slug damage, night checks, board traps and habitat removal. (The page also names baits; this course cites it for identification and non-chemical methods only.)
- Squash vine borers (University of Minnesota Extension): a full example of life cycle, monitoring, row cover timing and sanitation for one pest.
- Vegetable and Floriculture Diagnostics (UMass Amherst Extension): how one state's lab wants plant samples collected and sent.
7. Practice Practice
Minimum: Look up your extension office, choose a scouting day, do the first walk and log every crop, and check back next week; skip the night check, the threshold and the wildlife sheet. Time: about 30 minutes for the first walk, then 15 to 20 minutes a week. Materials: a phone for photos, a flashlight for one night check, a few zip-top bags and a small jar with a lid, a pencil, and the problem log.
- Find your help before you need it. Look up your county extension office through the Extension Foundation directory. Write its phone number, its diagnostic service's address or drop-off rules, and the NPIC number (1-800-858-7378) at the top of your problem log notes.
- Choose your scouting day. Pick a morning you can keep every week. Add it to the weekly checklist.
- Do the first walk. Follow the seven steps in Section 2. For each crop, log one row even if you saw nothing: "no damage" is data, and it dates the first appearance of anything later.
- Identify one thing. If you found damage, use the symptom table to list the likely causes and the confirming sign for each. Look for the sign. Write the identification and mark it provisional, confirmed or unresolved, with who identified it.
- Go deeper Do one night check. Go out after dark with a flashlight once in the first two weeks, even if nothing is wrong. You will see what lives in your garden at night.
- Go deeper Write a threshold. For your most valued crop, write in a sentence the damage you will accept before acting, and what you will do first if it is crossed (hand-pick, cover, fence, prune). This is your preference, recorded so you can compare it with what happens.
- Go deeper Log animals separately. If you have seen deer, rabbits, groundhogs or birds, add a row to the wildlife sheet with the sign, the damage and any barrier.
- Check next week. Revisit every row you logged. Add the result.
8. Your garden Your garden
9. Check your work Check your work
Criteria
- Does your problem log have a row for every crop from your first walk, including "no damage" rows?
- For every identification, is the status marked, and is the person or source that identified it named?
- Did you look for the confirming sign before writing an identification, and can you say which sign it was?
- Did you check soil moisture before calling a wilt a pest?
- Do you have your extension office's number and sample rules written down before a problem appears?
- Is your threshold written as an amount of damage and a first action, not as "if I see a bug"?
- If you are on a shared plot or rent, have you read the rules on pesticides and fences?
Worked example
Plot 14's log meets the criteria. The first row, Dale's slug guess, was marked provisional and credited to an internet photo, which is honest about its weight. The missing slime trails were the confirming sign that failed, and the night check found a different culprit. The identification moved to confirmed only when the county diagnostic service named it, and the log says so. The action taken (resowing and night checks) was least-risk and inside the garden's rules, and the open question about trapping went to the coordinator. The result column shows damage stopping by the third week. What the log does not show is why: larger plants, fewer earwigs, or both. That stays open for next season.
Common mistakes
- Treating before identifying. The most common and most expensive mistake. If you cannot name the confirming sign, you have not identified the problem.
- Trusting the photo match. Many problems look alike in a photo. Mark it provisional.
- Calling every insect a pest. Lacewing larvae, lady beetle larvae and syrphid fly larvae look strange and eat aphids. Identify before removing.
- Leaving a row cover on through bloom on squash, cucumber or melon. No pollinators, no fruit.
- Blaming a pest for a disorder. Blossom end rot and afternoon heat wilt have no culprit to find.
- Assuming "natural" means safe. Organic and homemade products are pesticides. The label is the law, and homemade mixes have no label.
- Skipping the result. An action without a follow-up check teaches you nothing for next year.
What is still unresolved
This module cannot identify a problem in your garden; your walk, the confirming signs and, when needed, a diagnostic lab can. It cannot tell you which product to use or whether one is allowed where you garden; the label, your extension office, NPIC and your garden's rules can. It cannot tell you what fence your local deer respect; your extension office's regional guidance and your own trial can. The pattern of problems over a season, and which ones come back, is reviewed in Module 12.