Overview: why timing matters for rust control Rust diseases are among the most damaging fungal problems in orchards because they reproduce rapidly, produce abundant windborne spores, and cause repeated infections during wet, warm periods. In Hawaii, island-scale and microclimate variation means infection windows vary by location, elevation, and cultivar. Correct timing of fungicide applications — […]
Hawaii presents a unique set of challenges for maintaining healthy turfgrass. Warm temperatures, humid air, frequent rain or irrigation, and a wide range of soil types from coastal sands to volcanic loams create ideal conditions for a variety of soil-borne pathogens. This article describes the principal soil-borne pathogens that damage turfgrass in Hawaii, explains how […]
Being deliberate about pest inspections turns reaction into prevention. In Hawaii, warm temperatures, high humidity, and frequent rains create ideal conditions for many garden pests and diseases. A regular inspection routine helps you detect problems early, protect plant health, and reduce dependence on broad-spectrum pesticides. This article provides concrete, step-by-step guidance for creating and maintaining […]
Creating habitat for beneficial insects in Hawaiian yards is both an ecological investment and a practical pest-management strategy. Hawaii’s islands host a unique mix of native and non-native species, and thoughtful yard design can support pollinators, predators, detritivores, and parasitoids that improve plant health, increase yields in edible gardens, and help restore ecological balance. This […]
Sooty mold on citrus is a common and unsightly problem in Hawaii, especially on young trees that have not yet developed a robust canopy or strong management history. The black, sooty film reduces photosynthesis, stresses trees, and signals a persistent sap-sucking pest infestation that must be addressed. This article explains the biology of sooty mold […]
Hawaii’s tropical climate, diverse soils, and year-round plant growth create both opportunities and challenges for growers, landscapers, and gardeners. Soil-borne insect pests such as fungus gnats, scarab grubs, root weevils, and mole crickets can reduce yields, damage ornamentals, and make turf and nursery production costly to manage. Beneficial (entomopathogenic) nematodes offer a biological, low-residue option […]
Coconut palms are iconic, resilient trees, but when trunk rot sets in the prognosis can be serious. Trunk rot is a progressive decay of the woody tissues and roots, usually driven by fungal pathogens and accelerated by wounds, poor drainage, or other stresses. Early detection and a decisive management plan can save a tree or […]
Bacterial canker on mango is an important disease to recognize in Hawaii because the islands’ warm, humid climate favors bacterial growth and spread. Identifying bacterial canker early helps growers limit yield loss, control spread to healthy trees, and avoid unnecessary treatments. This article describes what bacterial canker looks like on Hawaiian mango trees, how to […]
Understanding the problem: what a mealybug hotspot is Mealybug hotspots are localized areas in a landscape bed where mealybug populations become dense enough to cause visible plant decline, honeydew and sooty mold, and rapid spread to neighboring plants. In Hawaii’s warm, humid climate mealybugs can reproduce year-round, so hotspots tend to develop quickly in sheltered […]
Hawaii’s gardens are lush, diverse, and productive — and they are also excellent habitat for snails and slugs. Gardeners often encounter high densities of these mollusks, from tiny seedlings-nipping slugs to large invasive land snails. Understanding why snails and slugs do so well in Hawaiian gardens is essential for effective management and for protecting the […]
Bacterial leaf spot is a common and recurrent problem on many fruit trees in Hawaii. Warm temperatures, persistent humidity, and frequent rainfall create an environment that favors bacterial pathogens. Preventing bacterial leaf spot requires an integrated approach that combines sanitation, cultural practices, careful irrigation, targeted chemical use when necessary, and ongoing monitoring. The following guidance […]
Whiteflies are one of the most persistent and damaging insect pests on Hawaii vegetable crops. They cause direct feeding injury, honeydew and sooty mold problems, and they transmit serious plant viruses. Because Hawaii has warm, year-round growing conditions and a diverse mix of host plants, whitefly populations can build rapidly and develop resistance to chemical […]
Coconut palms are an iconic part of Hawaii’s landscape and economy, but they face a range of diseases that can rapidly reduce canopy value and kill trees if not managed promptly. This guide explains which diseases to watch for, when in the year to treat them, and what practical steps to use in an integrated, […]
Leaf spot diseases are among the most common and visually conspicuous problems of ornamental plants in Hawaii. Warm temperatures, frequent rainfall, high humidity and dense plantings create an environment in which a wide variety of pathogens produce leaf lesions that reduce aesthetic value, slow growth, and in severe cases cause defoliation and plant death. This […]
Overview: Why monitoring matters in Hawaiian orchards Hawaii’s warm, humid climate and frequent rainfall create ideal conditions for many fungal and bacterial pathogens. Orchards with dense canopies, overhead irrigation, poor drainage, or poor airflow are at especially high risk. Effective monitoring allows growers to detect disease early, target interventions precisely, reduce product loss, and limit […]
Hawaiian gardens exist in a unique climatic and ecological context: year-round warmth, high humidity in many locations, and a mix of introduced and native species. That combination supports vigorous plant growth but also a steady pressure from pests. Choosing organic repellents and deterrents helps protect pollinators, soil life, native fauna, and the long-term health of […]
Gardening in Hawaii offers year-round growing, abundant rainfall in many places, and a warm, humid climate that is ideal for both plants and plant pathogens. Because bacterial and fungal diseases thrive in warm, moist environments, tool sanitation is an essential cultural practice to prevent spread of diseases among plants, protect native species, and limit outbreaks […]
Hawaii growers face a persistent challenge from plant-parasitic nematodes — microscopic roundworms that feed on roots and reduce yields in vegetables, fruit trees, ornamentals, and pasture systems. Using cover crops as a tool to suppress nematodes is an effective, low-cost, and sustainable strategy well suited to Hawaii’s year-round growing conditions. This article explains how cover […]
Vegetable gardening in Hawaii offers year-round growing, rapid growth, and the pleasure of near-constant harvests. It also comes with year-round pest pressure: aphids, whiteflies, caterpillars (cabbage looper, armyworm), root-knot nematodes, slugs and snails in wetter areas, and a steady background of chewing and sucking insects. Choosing the right plants and planting patterns is one of […]
Fusarium wilt is one of the most important soilborne fungal diseases affecting many plant species worldwide. In Hawaii’s warm, humid environment it can cause sudden and severe damage to a wide range of tropical crops. This article explains what Fusarium wilt looks like in the field, how the pathogen behaves, how to distinguish it from […]
Scale insects are a pervasive pest on many Hawaiian ornamental plants. Their often cryptic appearance, waxy protections, and rapid reproductive cycles let populations build unnoticed until damage — leaf yellowing, sticky honeydew, sooty mold, twig dieback, or overall plant decline — becomes obvious. Home gardeners can control scale successfully with a practical, integrated approach that […]
Overview: the problem in Hawaiian landscapes Bark beetles and related wood-boring ambrosia beetles are increasingly important pests of shade trees in Hawaiian towns, parks, and agricultural settings. These insects are small, cryptic, and often overlooked until damage becomes obvious: branch dieback, sudden wilting, or numerous tiny holes and sawdust on the trunk. Understanding why shade […]
Coastal landscapes in Hawaii are uniquely beautiful and ecologically fragile. Warm temperatures, salt spray, and a mix of native and introduced plants create conditions where invasive pests can establish quickly and cause disproportionate damage. Preventing invasive pests on Hawaiian coastal plants requires practical, consistent action at the individual, property, and community levels. This article provides […]
Detecting plant diseases early is the single most important step you can take to protect a Hawaii garden. Tropical and subtropical climates make disease pressure high: warm temperatures, frequent rain, high humidity, and diverse insect vectors create a favorable environment for fungi, bacteria, viruses, and oomycetes. Early detection limits spread, reduces crop losses, and keeps […]
Hawaii’s climate supports year-round crop production and, unfortunately, year-round moth and caterpillar activity. Effective control of these pests relies less on calendar schedules and more on timely interventions that match pest biology, crop sensitivity, and local weather. This article provides a practical, in-depth guide to when and how to apply biological controls for moth and […]
Hawaii’s warm temperatures, high humidity, and frequent rains create near-ideal conditions for a wide range of fungal pathogens. Home gardeners on the islands must be prepared to recognize, prevent, and manage diseases that thrive in moist, tropical conditions. This article catalogs the most commonly encountered fungal and fungus-like pathogens in Hawaiian gardens, describes their symptoms […]
Invasive pests pose an acute and ongoing threat to the natural, agricultural, and cultural resources of the Hawaiian Islands. Early detection and accurate reporting are the most effective tools to slow or prevent establishment and spread. This article provides step-by-step, practical guidance for residents, land managers, and volunteers to monitor for invasive pests, properly document […]
Aphids are a common, persistent pest on ornamentals in Hawaii. Warm temperatures and year-round growing seasons let aphid populations build quickly, and honeydew and sooty mold can rapidly reduce the aesthetic value of landscape plants. This article describes practical, low-toxicity approaches you can use alone or in combination to manage aphids effectively while minimizing harm […]
Why drainage matters in Hawaii Hawaii’s climate and geology create unique challenges for plant health. Many parts of the islands receive intense tropical rainfall, while others are relatively dry. Soils range from fast-draining volcanic cinders and pumice to heavy clay or compacted fills in developed areas. Root diseases caused by water-loving pathogens such as Phytophthora, […]
Hawaiian landscapes present a unique combination of beauty, biodiversity, and vulnerability. Warm, moist conditions plus a long history of species introductions make islands especially prone to invasive pests. At the same time, Hawaii’s native flora and agricultural systems can benefit greatly from natural pest suppression provided by beneficial insects. This article explains which beneficial insects […]
Hawaii gardeners face a year-round pest pressure that is different from temperate regions: warm temperatures, high humidity in many zones, diverse insect communities, slugs and snails in wet areas, and fruit flies in orchards. Companion barrier planting uses living plants positioned and chosen to reduce pest damage by creating physical obstacles, masking host odors, repelling […]
Overview: why root-knot nematodes matter in Hawaii Root-knot nematodes (genus Meloidogyne) are microscopic soilborne roundworms that feed on plant roots and form characteristic galls. In Hawaii’s warm, often moist soils these nematodes reproduce rapidly and can be one of the most important yield-limiting pests for vegetables, ornamentals, sugarcane, and many tropical crops. Understanding what damage […]
Gardening in Hawaii presents unique challenges: year-round warmth, high humidity, intermittent heavy rain, volcanic soils, and microclimates across islands and elevations. When leaves display spots, yellowing, or necrosis, the cause may be a pathogen (commonly called “leaf spot”) or a nutrient deficiency. Correct diagnosis is essential because remedies differ — pruning and fungicide for a […]
Overview: the problem framed for Hawaiian growers Bacterial spot is a common and frustrating disease of tropical and subtropical fruit trees in Hawaii. It shows up as leaf lesions, fruit scarring, twig dieback and sometimes widespread defoliation or fruit losses that reduce marketability. The disease is caused by several species of bacteria in the genus […]
Understanding the problem: what scale insects are and why Hawaii is vulnerable Scale insects are a group of sap-feeding pests that attack leaves, stems, branches and sometimes roots of ornamentals. They range from soft, waxy forms that excrete sticky honeydew to armored types that produce a hard protective cover. In Hawaii’s warm, stable climate many […]
Orchid growing in Hawaii is uniquely rewarding and uniquely challenging. Warm temperatures, high humidity, and year-round plant growth create ideal conditions not only for orchids but also for a wide suite of insect and snail pests. Thrips are one of the most destructive insects for orchids: they feed in buds and flowers, create silvery streaks […]
What is powdery mildew? Powdery mildew is a common foliar disease caused by a group of unrelated fungi that produce a characteristic white to gray powdery coating on leaves, shoots, and sometimes flowers and fruit. Unlike many fungal diseases, powdery mildew fungi do not require free water on the leaf surface to infect. They thrive […]
Hawaii’s tropical climate and diverse agricultural systems make the islands vulnerable to a wide array of soil-dwelling and stem-boring beetles whose larvae or adults attack crop roots, corms, tubers, and lower stems. Effective management starts with knowing which types of beetles are most damaging, how to recognize their injury, and what evidence-based control tools are […]
Diagnosing viral diseases in ornamental plants requires a systematic approach that combines careful field observation, correct sampling, appropriate laboratory testing, and practical management decisions. In Hawaii, unique climatic conditions, high plant diversity, and movement of plants between islands make reliable diagnosis and rapid response particularly important. This article provides step-by-step guidance, technical details, and practical […]
Effective pest control in Hawaii’s landscapes must balance the islands’ unique ecosystems, year-round growing season, and community expectations for safety and aesthetics. Low-toxicity strategies reduce risks to people, pets, pollinators, and marine environments while still managing insects, snails, weeds, rodents, and invasive species. This article presents an in-depth, practical guide to integrated, low-toxicity pest control […]
Overview: Why ants matter in Hawaiian orchards Ants are a persistent and often underestimated threat to orchard health in Hawaii. Several non-native species, including Argentine ants and little fire ants, have become established and disrupt ecological balance, protect sap-sucking pests, and can directly damage fruit and crop production systems. Effective prevention focuses on interrupting foraging […]
Using native plants in Hawaiian landscapes and farms is one of the most effective, low-input strategies for reducing pest pressure while supporting biodiversity and cultural values. Native species evolved alongside local insects, birds, microbes, and climatic regimes for millennia; when we prioritize them in planting design and crop borders, we harness ecological processes that suppress […]
Hawaii’s climate — warm, humid, and varied across islands and elevations — favors both luxuriant plant growth and a wide array of plant pathogens. Choosing the right species and varieties is the single most effective long-term strategy to reduce losses to root rots, foliar fungal diseases, bacteria, viruses, and emergent threats. This guide explains the […]
Spider mites are small arthropods that cause outsized damage to many Hawaiian crops. They thrive in warm, dry conditions, reproduce rapidly, and can hide on the undersides of leaves until populations are large. This article explains exactly what spider mite damage looks like across Hawaiian crop types, how to confirm the pest, the biology and […]
Understanding nematodes and the Hawaii context Plant-parasitic nematodes are microscopic roundworms that attack roots and reduce plant vigor, yield, and quality. In Hawaii, the warm climate, diverse cropping systems, and year-round growing seasons create favorable conditions for several important plant-parasitic species, including root-knot nematodes (Meloidogyne spp.), lesion nematodes (Pratylenchus spp.), sting and dagger nematodes (Belonolaimus […]
Scale insects are among the most persistent and damaging pests of ornamental plants in Hawaii. Their small size, protective coverings, and life history traits make them both difficult to detect and difficult to control. In the Hawaiian landscape, a combination of climate, horticultural practice, host availability, and disrupted ecological balance creates near-ideal conditions for scale […]
Root rot is one of the most persistent and costly problems for tropical gardens in Hawaii. Warm temperatures, periodic heavy rains, and rich organic soils create an environment in which root-rotting pathogens such as Phytophthora, Pythium, Rhizoctonia, and fungal complexes can thrive. This article provides practical, field-tested strategies for preventing and managing root rot in […]
Mealybugs are a persistent pest for houseplant growers everywhere, but Hawaii’s warm, humid climate and year-round plant growth create especially favorable conditions for them. Preventing mealybugs is far easier, safer, and less costly than trying to eradicate an entrenched infestation. This guide provides in-depth, practical steps tailored to Hawaii houseplant culture so you can keep […]
Gardening in Hawaii is a joy and a challenge. Warm temperatures, high humidity, and frequent rains create ideal conditions for many fungal and oomycete diseases. Knowing when to apply fungicides is as important as knowing what product to use. Timely application minimizes plant damage, reduces repeated treatments, and helps prevent resistance. This article provides practical, […]
Hawaii’s unique flora evolved in long isolation and is exceptionally vulnerable to invasive pests. The archipelago’s native plants include many endemic species found nowhere else on Earth, and those species are at heightened risk from a variety of introduced animals, insects, mollusks, and pathogens. This article describes the principal categories of invasive pests that threaten […]
Hawaii’s unique island environment creates a set of challenges and opportunities for diagnosing plant disease. Warm temperatures, high humidity in windward areas, frequent cloud cover, and sharply varying microclimates across short distances mean that symptoms often progress quickly and multiple agents can cause similar signs. This article presents a practical, step-by-step diagnostic workflow for leaf […]
Aloha gardeners. Hawaii’s climate, island ecosystems, and unique mix of native and introduced species create pest management challenges different from mainland gardens. High humidity, frequent rains, warm year-round temperatures, and an abundance of invasive pests mean organic gardeners must rely on a suite of cultural, physical, biological, and botanical tools rather than a single silver […]
Hawaii’s climate is ideal for growing a wide range of fruit trees, but warm temperatures and year-round growing conditions also favor a long list of pests. Successful protection is not a single trick but an integrated, repeated set of cultural, physical, biological, and, when necessary, chemical tactics. This article explains practical, safe, and locally effective […]
Integrated Pest Management (IPM) is a science-based, decision-making framework that uses multiple tactics to manage pests while minimizing risks to people, property, and the environment. In Hawaii, landscapes face a unique combination of year-round warmth, high humidity in many areas, diverse native and introduced plants, and a long history of invasive species. Those factors make […]
Moth pests can be one of the most persistent and economically damaging problems in Hawaii orchards. The combination of warm temperatures, year-round plant growth, and varied microclimates across islands and elevations allows many lepidopteran pests to reproduce continuously and shift rapidly between host crops. Effective control requires an integrated approach — monitoring and correct identification, […]
Stem rot is a common and destructive problem in Hawaii because of the islands’ warm, humid climate and frequent rains. It is not a single disease but a set of symptoms caused by a variety of fungi and fungus-like organisms. Recognizing stem rot early, knowing which pathogens are likely in Hawaii, and applying appropriate cultural […]
Citrus in Hawaii faces a unique combination of tropical climate, island ecosystems, and a long history of both endemic and introduced pests and pathogens. Effective treatment depends on accurate identification, prompt action, and an integrated approach that combines cultural, biological, and chemical tactics while following state regulations. This article provides practical, Hawaii-specific guidance for recognizing, […]
Hawaii’s gardens and agricultural fields are famously lush, colorful, and productive. They are also magnets for an unusually broad suite of pests. Home gardeners, landscapers, and farmers often ask why tropical plants in Hawaii seem to suffer more pest pressure than similar plants in temperate regions. The answer is not a single cause but a […]
Hawaii’s climate–warm temperatures, frequent rain, and high humidity–creates ideal conditions for many fungal pathogens. Gardeners in the islands must combine cultural know-how, vigilant monitoring, and targeted interventions to keep plants healthy. This article provides practical, concrete methods to prevent fungal diseases in home and community gardens across Hawaii, with plant-specific notes where relevant, and clear […]
Hawaii’s warm, humid climate supports an abundance of plant life — and a similarly abundant suite of insects and other organisms that feed on those plants. Correctly identifying pests is the first step toward effective, low-impact control. This guide covers the most common plant pests you will encounter in Hawaiian gardens and landscapes, how to […]