The sudden appearance of damage on your daisy plants indicates your garden has become a feeding ground for local wildlife or various insect pests. Successfully protecting your daisies requires accurately identifying the specific culprit responsible for the chewing, tearing, or holing of your plants. This diagnostic step determines whether you need a physical barrier for a larger animal or a targeted treatment for a minuscule pest.
Diagnosing the Damage: Identifying the Culprit
The size and shape of the damage offers the first and most telling clue about the animal responsible. Large mammals like rabbits and deer create distinct patterns due to their dental structures. Deer lack upper incisors, which forces them to tear foliage, leaving behind ragged, uneven edges on stems and leaves, often on damage up to six feet high. Rabbits, however, have sharp incisors that produce clean, angled cuts on stems, similar to a pruning shear, typically within a foot or two of the ground.
If the damage involves small, irregular holes in the leaves or flowers, the problem is likely an insect or mollusk. Slugs and snails are confirmed by the silvery, dried mucus trails they leave across leaves and soil, as they are nocturnal feeders that seek damp conditions. The presence of small, dark, pellet-like droppings is a definitive sign of feeding caterpillars. These larvae chew large, ragged holes through leaves, often leaving the major veins intact.
Tunnels or disturbed soil near the base of the plants suggests the presence of voles or groundhogs, which may target roots or the lower stems. Nocturnal insects like earwigs also chew irregular holes in petals and leaves. Their activity can be confirmed by checking the plants after sunset with a flashlight, which helps narrow the field to nocturnal feeders.
Management Strategies for Mammalian Pests
Physical exclusion is the most reliable method for deterring larger garden marauders like rabbits and deer. To stop rabbits, a low fence constructed of galvanized wire mesh is necessary, but it must be at least two feet high. The bottom six inches of this barrier should be buried underground to prevent them from digging beneath it. Placing the fence material outward in an L-shape underground maximizes the deterrence against burrowing.
Protecting daisies from deer requires a taller physical barrier, reaching eight feet in height. Because a fence of this size is often impractical, a common strategy involves using scent and taste repellents. The most effective commercial products contain putrescent egg solids, which signal a predator presence to the deer. These repellents must be applied directly to the foliage and require reapplication every few weeks, particularly after heavy rain or new plant growth.
Woodchucks and groundhogs require focused exclusion below ground level. To deter them from entering a specific area, bury a perimeter of half-inch hardware cloth at least 12 to 18 inches deep. The cloth should be bent outward at a 90-degree angle, extending 18 to 24 inches horizontally into the soil to create a subterranean barrier. Combining this exclusion method with strong-smelling repellents placed near active burrows can encourage them to relocate their dens.
Controlling Slugs, Snails, and Destructive Insects
Controlling slugs and snails can be achieved through manual and targeted chemical means. Iron phosphate baits are widely used because they are less toxic to birds and mammals than older molluscicides. Non-chemical methods include sinking a shallow dish of beer into the soil, which attracts and drowns the pests, providing a simple, targeted trap.
For caterpillars, biological control is effective. Sprays containing Bacillus thuringiensis subspecies kurstaki (Btk) target only caterpillars and are harmless to beneficial insects. The caterpillar must ingest the bacterium, which paralyzes its digestive system, causing it to stop feeding immediately. Btk is most effective when applied in the late afternoon or evening, as the bacteria quickly degrade in direct sunlight.
Earwigs and grasshoppers can be managed using mechanical barriers and traps. Diatomaceous earth (DE) works by scratching the insect’s protective outer layer, leading to fatal dehydration. Apply a light dusting of food-grade DE around the base of the affected daisies, but remember that it becomes ineffective once wet and must be reapplied after rain. Simple traps made of a shallow container filled with vegetable oil and a few drops of soy sauce can also attract and eliminate earwigs searching for a hiding spot.
Long-Term Garden Protection and Prevention
Modifying the garden environment makes the area less appealing to pests. Since many pests thrive in damp conditions, reducing excess moisture is beneficial. This involves using drip irrigation instead of overhead sprinklers and ensuring that mulch is not piled directly against the daisy stems. Removing garden debris like fallen leaves, old boards, and excess weeds eliminates the moist, dark hiding spots preferred by slugs, snails, and earwigs.
Companion planting uses the strong aromas of certain herbs to mask the attractive scent of your daisies. Planting herbs like lavender, mint, rosemary, or garlic chives near vulnerable flowers can deter both browsing mammals and insects. Deer and rabbits avoid these pungent plants, and their strong oils confuse pests attempting to locate their preferred food source.
Encouraging the presence of natural predators provides long-term pest management. Birds, toads, and ground beetles all consume slugs, snails, and insect larvae. Avoiding the use of broad-spectrum chemical pesticides protects these beneficial allies, allowing them to establish a natural balance within your garden ecosystem.