Pesticides are a vital part of any landscaper’s toolkit. When used safely and effectively, pesticides help lawns, gardens, and client properties thrive by controlling unwanted pests. However, proper pesticide application and knowledge are essential to protect people, pets, and the environment.

Horizon has created this comprehensive pesticide guide for landscapers and lawn care professionals looking to protect and enhance their clients’ outdoor spaces.

What Are Pesticides for Landscaping?

When most people think of pesticides, they picture sprays that target insects or weeds. However, the term “pesticide” refers to a broad category of products designed to control or eliminate a wide range of pests in landscapes and gardens.

The Department of Health defines a pest as: “any animal or plant which has a harmful effect on humans, their food or their living conditions.”
Common pests affecting landscapes include:

  • Insects that damage grass and ornamental plants

  • Weeds competing with desirable plants

  • Rodents that destroy landscapes or spread disease

  • Fungi causing plant diseases

Other Examples of Pests in Lawns and Gardens:

  • Damage to clothing or buildings

  • Biting or stinging people or pets

  • Spreading diseases

  • Damaging crops and stored food

  • Attacking or eating farm animals

While insects are the most common threat, pests can also include invasive plants, fungi, and various animals.

Types of Pesticides Used by Landscapers

Not all pesticides are alike. Each type is specially formulated for specific pests and conditions. Understanding the right pesticide for your landscaping needs is key to effective and safe pest control.

Main Categories of Pesticides:

  • Herbicides: Target and remove weeds and invasive plants

  • Insecticides: Control harmful insects (mosquitoes, ants, beetles)

  • Rodenticides: Manage mice, rats, and other rodents

  • Fungicides: Treat plant diseases caused by fungi

Herbicides: Effective Weed Control for Landscapers

Herbicides are essential for managing unwanted plants, especially invasive weeds, in lawns and landscapes. Through a process called “selectivity,” many herbicides specifically target unwanted weeds while protecting desirable turfgrass and ornamentals. Herbicides work by disrupting certain enzymes within the weed, causing buildup of toxins and eventual plant death.

Types of Herbicides Offered by Horizon

  • Pre-emergent Herbicides: Used to prevent weed seeds from germinating. These should be applied when soil temperatures reach 55°F and must be thoroughly watered in to activate. Pre-emergent weed killers are ideal for proactive lawn care.

  • Post-emergent Herbicides: Designed to kill already existing weeds. They are further divided into:

    • Selective Herbicides: Target specific weed types without harming lawn grasses—crucial for turf management.

    • Non-selective Herbicides: Kill any plant they contact, making them suitable for spot treatments but risky near desired vegetation.

  • Aquatic Herbicides: Control aquatic weeds and algae in ponds, lakes, or fountains, with formulas that avoid groundwater contamination and protect aquatic wildlife.

Effective weed control depends on:

  • Identifying the weed species.

  • Understanding the type of turfgrass or vegetation present.

  • Knowing the weed's life cycle to choose between pre-emergent and post-emergent treatments.

Be cautious of wind drift when applying herbicides, especially non-selective formulations, to prevent damage to desirable plants.

Tip: Always follow the manufacturer’s label for safe herbicide application and optimal results.

Insecticides: Eliminating Insects in Lawns and Gardens

Insects not only create annoyances for clients but can also damage grass, flowers, trees, and shrubs. Effective insect control is crucial for healthy landscaping.

Common Lawn and Garden Pests Controlled by Insecticides:

  • Wasps and hornets

  • Mosquitoes

  • Slugs and snails

  • Pill bugs and saw bugs

  • Ants (fire ants, carpenter ants, etc.)

  • Aphids and mealybugs

  • Crane flies (mosquito hawks)

  • Armyworms, cutworms, leafminers

  • Fleas and ticks

  • Beetles and caterpillars

  • Grasshoppers and termites

Typical Signs of Insect Infestation:

  • Brown or dead patches in grass

  • Wilting or damaged plants and leaves

  • Bite marks on grass blades or leaves

  • Itchy or restless pets (possible flea/tick presence)

Educate your clients about these signs and offer professional pest control solutions tailored to their landscape’s needs.

How Insecticides Work

According to insect experts, such as Entomologist Dr. Alan T. Eaton, insecticides kill or deter pests in several ways:

  • Attacking the nervous system

  • Interrupting growth or maturation

  • Blocking oxygen absorption

  • Coating plants so insects consume the pesticide when feeding

Professional-Grade Insecticides from Horizon

Horizon provides a reliable selection of commercial-grade insecticides suitable for lawns, gardens, ornamental plants, sports fields, golf courses, and more.

Featured Product:
Mallet® 0.5G Turf Insecticide – Delivers fast, broad-spectrum, long-lasting grub and insect control with both preventive and curative benefits. Effective for grubs, billbugs, European crane flies, and more. (Always read and follow label instructions.)
 

Herbicides

Rodenticides: Safe Rodent Control in Landscaping

Rodenticides are pesticides formulated to manage rodent populations—such as rats, mice, gophers, squirrels, rabbits, and chipmunks—that can damage lawns and landscapes. While rodents have ecological benefits, overpopulation can result in significant property and plant damage.

Key Solutions for Rodent Control

  • Poison Baits in Tamper-Resistant Stations: These combine food attractants with rodenticidal ingredients. Stations protect non-target animals, pets, and children from accidental exposure.

  • Traps: From baited traps to set-and-release options, traps help control rodents like gophers and moles.

  • Animal Repellents: Non-lethal solutions for keeping rodents and other animals such as deer and rabbits away without harm.

Signs of Rodent Damage:

  • Tunneling in lawns

  • Raised lawn sections

  • Damaged plants and disrupted root systems

  • Ragged or stripped bark on trees and shrubs

Educate your clients about rodent-related landscape damage. Horizon provides a wide variety of rodenticides, traps, and humane repellents for professional landscape pest management.

Important: Always use rodenticides according to label directions to protect humans, pets, and wildlife.

Fungicides: Disease Control for Lawns and Ornamentals

Fungi such as rusts, molds, mildews, and blights can devastate lawns, gardens, and ornamental beds. Fungicides are specialized pesticides that prevent or eliminate fungal pathogens affecting turf, flowers, shrubs, and trees.

Common Lawn and Plant Diseases Caused by Fungi

  • Anthracnose

  • Brown Patch

  • Dollar Spot

  • Leaf Spots & Blights

  • Powdery Mildew

  • Snow Molds

  • Summer Patch

  • Stem, Crown, and Root Rot

  • Necrotic Ring Spot

Fungicides target fungi by disrupting cell membranes or interfering with energy production, effectively stopping fungal growth and disease spread.

Smart Fungicide Use in Landscaping

When using fungicides—especially for golf course turf, ornamentals, and high-value landscapes—it’s essential to prevent the development of fungicide resistance. Rotating products with different FRAC codes (Fungicide Resistance Action Committee identifiers) helps limit cross-resistance, ensuring ongoing effectiveness.

Horizon’s expertise: Our team assists landscape professionals in selecting the right fungicide and creating resistance management programs for comprehensive lawn and plant disease control.

Safe & Legal Application of Pesticides

Best Practices for Landscapers:

  1. Always follow label directions.
    Application methods must comply with both state and federal pesticide laws.

  2. Use personal protective equipment (PPE) when handling or applying pesticides.

  3. Store products securely—away from children, pets, and water sources.

  4. Educate your staff and clients on the importance of safe, responsible pesticide use.

Applying pesticides in any way not specified on the label is illegal and can be hazardous to people, pets, and the environment.

Still not sure which pesticide options are best for you?   Horizon helps landscape professionals prescribe the best pesticide solutions for their properties. Contact us today to learn more!