Asparagus, a highly prized garden vegetable, offers a unique flavor and signals the arrival of spring with its tender spears. This perennial plant, known for its rewarding harvests, can unfortunately attract the attention of various creatures. From tiny insects to larger mammals, several animals are known to feed on asparagus plants, potentially impacting the anticipated yield.
Common Insect Pests
Asparagus plants are frequently targeted by specific insect pests, each leaving distinct signs of their presence. The common asparagus beetle, measuring about 6-8 millimeters, has a metallic-blue head, a red thorax with two blue spots, and bluish-black wing covers featuring three yellowish square spots. Both adult common asparagus beetles and their larvae consume spears and ferns, causing scarring, browning, staining, and bent growth, sometimes leading to defoliation. The larvae also secrete a black fluid that can stain the plant. Eggs of the common asparagus beetle are black to greenish-brown and laid in neat rows, perpendicular to the plant.
The spotted asparagus beetle, a related pest, is orange-red with twelve black spots on each wing cover. While adults may feed on spears, their larvae primarily consume asparagus berries. These beetles typically emerge later in the season compared to their common counterparts, and their light-colored eggs are deposited singly on stems.
Asparagus miners are small, shiny black, humpbacked flies, roughly 0.1 inches long. Their larvae tunnel just beneath the surface of spears or stems, often near the base of the plant. This tunneling creates characteristic discolored, reddish-brown serpentine patterns. Although the damage is often cosmetic, the tunneling can girdle the stalk, causing the foliage to yellow, and asparagus miners are known vectors for Fusarium root and crown rot.
Cutworms, which are gray to tan caterpillars, can grow up to two inches long and typically curl into a C-shape when disturbed. These nocturnal feeders primarily sever young spears at the soil line, often during the night. They can also cause small holes or curling on spear tips, with some species feeding at the base and resulting in crooked spears.
Slugs and snails, soft-bodied mollusks up to four inches long, also pose a threat to asparagus. They prefer tender new growth, leaving irregular holes and a shiny mucus trail as they move across the plant surfaces. Their feeding can distort the growing tips of asparagus.
Mammalian Wildlife
Larger animals also find asparagus appealing, with their feeding habits leaving distinct traces. Deer are opportunistic feeders drawn to the tender new shoots of asparagus, especially in early spring when other food sources are limited. Their feeding typically results in ragged tears on the plants, rather than clean cuts, and they can browse plants up to six feet high. While asparagus is often considered deer-resistant, it is not entirely immune, and deer will consume it if preferred foods are scarce.
Rabbits are known to nibble young asparagus spears cleanly at or near ground level. Their damage is characterized by clean, 45-degree angled cuts on young stems, and they can reach approximately three feet high. The presence of distinctive round droppings in the immediate area can also indicate rabbit activity. Rabbits, like deer, are often most active during the night.
Groundhogs, also known as woodchucks, are herbivores with a broad diet that includes asparagus. They can consume significant portions of plants quickly. Their extensive burrowing can also disrupt the root systems of plants. Although asparagus might not be their primary food choice, groundhogs will eat it, particularly when other favored vegetation is less available.
Voles and mice are small, mouselike rodents that primarily gnaw on roots, bark, and bulbs. However, they may occasionally gnaw on underground crowns or newly emerging spears, leaving behind paired grooves from their incisor teeth. These rodents are nocturnal and remain active throughout the year.
Other Occasional Eaters
Less common, but still possible, are occasional feeders that might sample asparagus. While not considered primary pests, some bird species might occasionally peck at the tender tips of asparagus spears. Any significant damage from birds is generally rare.
Domestic animals, such as dogs and cats, might also occasionally nibble on asparagus spears out of curiosity. Asparagus is generally considered safe for dogs in small quantities. However, raw asparagus can be tough and may pose a choking hazard or cause digestive upset for pets; therefore, steaming or boiling and cutting it into small pieces is advisable. It is important to note that the “asparagus fern” or foliage of the plant is considered toxic to dogs and should be avoided.