Plant problems
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There are two ways into this section. If you know what you are looking at, start from the name of the pest or the disease. If you only know what the plant is doing - yellowing leaves, brown tips, holes chewed through a leaf, sudden wilting - start from the symptom, because one symptom usually has several possible causes and the page will show you which ones fit. What this section does not do is tell you what your plant is. The site does not name a species from a photograph or a description, and a problem page will not guess one for you. Symptoms also overlap in ways that are easy to misread: the same brown leaf edge can come from too little water, from salts built up in the compost, or from a root problem that began weeks before anything showed above ground.
Everything in this section
- DiseaseAnthracnose
- DiseaseApple scab
- DiseaseBlack spot
- DiseaseCedar-apple rust
- DiseaseCrown gall
- DiseaseDamping off
- DiseaseDowny mildew
- DiseaseEarly blight
- DiseaseFire blight
- DiseaseFusarium wilt
- DiseaseGray mold
- DiseaseLate blight
- DiseaseLeaf spot
- DiseasePowdery mildew
- DiseaseRoot rot
- DiseaseRust
- DiseaseSooty mold
- PestAphids
- PestCabbage worms
- PestColorado potato beetle
- PestCucumber beetles
- PestCutworms
- PestDeer
- PestFlea beetles
- PestFungus gnats
- PestJapanese beetles
- PestLeaf miners
- PestMealybugs
- PestRabbits
- PestScale insects
- PestSlugs and snails
- PestSpider mites
- PestSpotted lanternfly
- PestSquash bugs
- PestSquash vine borer
- PestThrips
- PestTomato hornworms
- SymptomBlack spots on leaves
- SymptomBlossom end rot
- SymptomBolting
- SymptomBrown leaf tips
- SymptomBrown spots on leaves
- SymptomCurling leaves
- SymptomDrooping leaves
- SymptomHoles in leaves
- SymptomLeaf drop
- SymptomLeaf scorch and sunburn
- SymptomLeggy growth
- SymptomMold on soil
- SymptomMushy stems
- SymptomNo flowers
- SymptomSticky leaves
- SymptomStunted growth
What's here
Every problem page sets out the symptoms recorded for that pest or disease, what causes them, the conditions that favour it, how to treat it, and how to keep it from coming back. Treatments are ordered the way the extension sources order them: cultural changes first, then physical and biological controls, then chemical ones last. Each one is cited to the source that recommends it, with the date that source was read, so you can see how current the advice is and check it yourself. Where a page mentions a pesticide, or any other product applied to a plant, it defers to the product label. The label is the legal instruction in the United States, it is specific to the product in your hand, and it overrides anything written here. Rates, intervals and the list of plants a product may be used on are deliberately not repeated on this site, because a number copied from one label and applied to a different product is how people and plants get hurt. The pages below are grouped by kind: insects and mites, diseases caused by fungi, bacteria and viruses, and the disorders that come from growing conditions rather than from any organism at all. That last group is the one most often mistaken for a pest.