What's Eating Your Sweet Potato Vine?

Tiny white moth-like insects, 1 to 2 mm long, that lift in a small cloud when you brush the trailing stems. Nymphs are flat translucent scales pasted to the underside of the heart-shaped leaves. Populations build fastest on plants in containers and hanging baskets where airflow is poor.

Lower leaves yellow and drop, and a sticky honeydew coats every leaf and stem below the infestation. Sooty black mold follows, masking the chartreuse or purple foliage colors that make sweet potato vine worth growing. Heavy populations stunt the vine and can collapse a container planting by late summer.

Tiny shiny black beetles, 2 to 3 mm long, that hop away like fleas when you approach. The sweet potato flea beetle is the most common species in the southern US. They feed on the upper leaf surface, leaving distinctive pinprick damage. Larvae feed underground on the roots.

Leaves develop a peppered shotgun pattern of tiny round holes, sometimes hundreds per leaf, that gives the foliage a lacy or scorched look. Heavy beetle pressure can yellow whole vines, and the underground larvae scar the tubers on edible plantings. Damage is heaviest early in the season on transplanted slips.

Soft pear-shaped insects 2 to 3 mm long, in green, black, or melon-yellow, packed on the soft new shoot tips where the trailing stems are still growing. They cluster at the growing points before the leaves fully expand.

New leaves emerge twisted and stunted, often with a sticky honeydew coating that draws sooty mold. Aphids also vector sweet potato feathery mottle virus, which mottles the leaves with yellow and reduces vigor. On chartreuse cultivars, virus mottling is hard to tell from natural variegation, so prevention matters.

Large green caterpillars 3 to 4 inches long with diagonal markings and a horn or eye-spot at the tail end. The sweet potato hornworm and tobacco hornworm both feed on sweet potato vine. They camouflage perfectly against the leaves and are easier to find by the dark pellet droppings on lower foliage and soil.

Whole sections of vine stripped to the bare stem overnight, often working inward from one trailing tip. Large dark green pellet droppings, the size of small peppercorns, accumulate on the leaves and soil below the feeding caterpillar and are usually the first clue.

Unmistakable up close. A 3 to 4 foot tall brown mammal. Most active at dawn and dusk. Damage is unmistakable on the ground: trailing stems clipped off mid-vine, sometimes with hoof prints in the mulch nearby.

Whole trailing stems disappear overnight, with ragged torn ends rather than the clean cuts a rabbit would leave. Deer browse from above and can reach 4 to 5 feet up a planter on a wall. Damage clusters near where deer enter and exit the yard.