Morning glories (Ipomoea) are vigorous, climbing vines prized by gardeners for their fast growth and brilliant, trumpet-shaped flowers that unfurl with the morning sun. While these plants quickly cover trellises and fences, their abundant foliage and tender shoots attract animals seeking an easy meal. Understanding which creatures are responsible and the specific signs they leave behind is the first step toward effective mitigation and protecting your plants.
Identifying the Culprits: Mammals and Gastropods
Damage from larger animals like mammals is easy to identify due to its scale, involving clean cuts or large sections of missing foliage. Deer are frequent browsers, feeding on the upper parts of the vine and consuming leaves and flower buds high up on a trellis. These animals leave large, ragged tears since they lack upper incisor teeth and rip the vegetation during feeding. Rabbits prefer to feed closer to the ground, leaving a diagonal, clean cut on young, tender stems and leaves at a low height.
Rodents, including squirrels, chipmunks, and rats, can also cause significant damage by severing stems entirely. Chipmunks and squirrels “behead” young vines, taking the newly cut sections away to consume elsewhere, which can result in entire morning glory plants suddenly collapsing. They are also drawn to the seeds, which they may consume directly from the developing pods.
Gastropods, such as slugs and snails, leave a different pattern of destruction, focusing on the most tender new growth and emerging leaves. Their feeding results in irregular, ragged holes in the foliage, rather than the clean cuts left by rodents. Evidence of their presence is the silvery, dried slime trail they leave behind as they move across the plant and the surrounding soil. Since these pests are nocturnal, the damage is discovered before the culprit is seen.
Identifying the Culprits: Insect Pests
Insect damage can be categorized based on the method of feeding, with some pests chewing through tissue and others extracting plant fluids. Chewing insects include caterpillars, such as the morning glory leafcutter, which may sever entire leaf stalks or consume large sections of the leaves, leaving behind holes. The golden tortoise beetle, a small, metallic-looking insect, also chews small to medium-sized holes directly into the leaf tissue. Leaf miners create distinctive serpentine tunnels or trails within the layers of the leaf as they feed, causing discolored and damaged patches.
Sucking pests use sharp mouthparts to pierce the plant tissue and extract sap, leading to different visual symptoms. Aphids and whiteflies cluster on new growth, draining the plant’s resources and causing leaves to yellow, crinkle, or become stunted. They excrete honeydew, a sugary waste product that promotes the growth of sooty mold, hindering photosynthesis. Spider mites are tiny arachnids that feed on the undersides of leaves, resulting in fine stippling or bronzing of the foliage and sometimes creating fine webbing across the stems and leaves.
Leafhoppers are another type of sucking insect whose feeding can cause the leaves to curl or distort. Their presence is concerning because they can also transmit viral diseases between plants. Insect damage is localized (holes or discoloration), unlike mammalian damage, which involves removing large portions of the plant or severing main vines.
Stopping the Damage: Exclusion and Repellents
Fencing is effective against rabbits and deer, but it must be high enough (six to eight feet) and have a fine mesh that extends partially below ground level to stop burrowing animals. For young plants vulnerable to cutworms or rodents, creating a protective collar from a plastic soda bottle and sinking it into the soil around the stem can prevent severing at the base.
For smaller pests, a strong jet of water (syringing) is a simple physical method that can dislodge aphids and spider mites from the foliage. For slugs and snails, exclusion can involve placing copper tape around the perimeter of planters, as the metal reacts with their slime and creates a mild electric shock. Diatomaceous earth, a natural powder, can also be sprinkled around the base of plants; this material causes physical damage to crawling pests.
Repellents and biological controls deter feeding without causing harm to the pests. Repellents containing capsaicin, the compound that gives chili peppers their heat, can be sprayed on foliage to discourage browsing mammals. Introducing natural predators, such as ladybugs or lacewings, provides a biological control method by encouraging them to feed on pests. Applying organic treatments like insecticidal soap or neem oil directly onto the pests helps manage populations without relying on harsh chemical pesticides.
Understanding Morning Glory Toxicity and Plant Health
Toxicity
Morning glories contain indole alkaloids, including Lysergic Acid Amide (LSA), which are concentrated mainly in the seeds. These compounds are toxic to domestic animals like dogs, cats, and horses, and ingestion can lead to symptoms such as vomiting, diarrhea, and, in large quantities, hallucinations. While the leaves and stems contain lower concentrations of these alkaloids, their ingestion can still cause gastrointestinal distress in pets and livestock. This inherent toxicity may be why some animals avoid extensive browsing on the foliage.
Maintaining Plant Health
Maintaining robust plant health is a long-term preventative measure that allows morning glories to better withstand minor pest pressure. Proper soil management and consistent watering ensure the plant has the resources to quickly recover from localized damage. Ensuring good air circulation around the vines by providing adequate spacing and avoiding overcrowding helps prevent common fungal diseases like powdery mildew. Watering the plants at the base, rather than using overhead watering, reduces the moisture on the leaves, limiting the conditions favorable for rust and other fungal infections.