Dogs, Marigolds & Pest Control

Marigolds are bright orange and yellow flowers native to Mexico. They are a hardy species of annual flowering plant that can survive hot, dry summers and bloom all summer long. Marigolds have a peculiar, pungent aroma that is considered by some to be unpleasant. Their scent is believed to deter dogs and cats from getting into flower gardens, where they like to dig in the dirt or lie on the flowers and use them as a bed.

  1. Dog and Marigolds

    • According to the ASPCA, pot marigolds (Calendula officinalis), commonly called Mary Bud or Gold bloom, and Cape marigolds (Dimorphotheca pluvialis), commonly called African daisies, are nontoxic to dogs. Annual marigolds such as French marigolds (Tagetes patula) and their taller more aromatic cousins, African marigolds (Tagetes erecta), are thought to have a pungent odor that repels dogs. At the time of publication, there had not been sufficient scientific research done on the toxicity of French marigolds or African marigolds to suggest that they are toxic to dogs. However, these two types of marigolds can induce an allergic reaction such as a skin rash or asthma symptoms in some people, so if you have a dog that is highly sensitive and suffers from allergies, you may not want to plant them in your yard.

    Marigold Types

    • Pot marigolds (Calendula officinalis) are larger than French and African marigolds and have flowers similar in shape to those of daisies, with long narrow leaves. These types of marigold come from the Mediterranean, and, according to Cornell University, they are safe to eat. French marigolds are short and bushy with fernlike spiky-edged leaves. The French marigold's pom-pom shaped flowers have a fragrance that is described as spicy or unpleasant. African marigolds are the tallest of the marigolds; they have a strong pungent scent that is thought to deter dogs, deer and rabbits. Dwarf or signet marigolds (Tagetes tenuifolia) grow to be 3 inches to 6 inches tall and are covered with small fragrant flowers. Signet marigolds are nontoxic to people and are also edible. Unfortunately, deer and rabbits like to eat them, too, so they are not a useful garden pest deterrent.

    Garden Pest Control

    • Nematodes are microscopic garden pests. They are smooth, unsegmented parasitic worms that live in the soil and eat and kill the roots of many garden and ornamental vegetables. The roots of French marigolds or French dwarf marigolds release chemicals into the soil that are toxic to nematodes. These types of marigolds are interplanted between rows of strawberries, potatoes and roses, which are often attacked by parasitic nematodes. Marigolds are also thought to ward off mammal garden pests such as cats, deer, dogs and rabbits as well as insects such as thrips, whiteflies, Mexican bean beetles, tomato hornworms and squash bugs.

    How to Plant

    • When planting marigolds to protect your garden from your dog or other pests, plant them in full sun, where they can get a minimum of six hours of sunlight each day. French marigolds require a space of 6 inches to 9 inches wide to accommodate growth, and African marigolds require up to 18 inches of space for growth. African marigolds grow quite tall and have large, heavy flowers that can grow to be up to 5 inches across and may cause the stem to bend. When this happens, use a stake to hold the plant erect.