What's eating my begonia × tuberhybrida 'nonstop rose'?

Begonia × tuberhybrida 'Nonstop Rose' grows from tubers and is especially vulnerable to vine weevil larvae, which destroy roots in containers. Slugs and snails attack the fleshy foliage and petals. Aphids and thrips mark the showy double blooms. Start nematode treatments in late summer to protect the tuber for overwintering.

Larvae (white grubs) eat tubers and roots through summer and autumn, causing stems to collapse; adults notch leaf edges at night. Apply pathogenic nematodes (Steinernema kraussei) to moist compost from late summer; check tubers before storage; use a free-draining gritty mix to deter egg-laying.

Holes in succulent leaves and petals, especially at the base of the plant; slime trails visible in the morning. Scatter iron-phosphate pellets; use copper tape on pots; hand-pick at night; apply diatomaceous earth around the base.

Colonies on shoot tips and inside double blooms; honeydew and sooty mold dirty the rose-pink flowers. Spray with insecticidal soap or neem oil; dislodge with water; encourage ladybirds as natural predators.

Silver or brown streaks on petals; double flowers look papery or fail to open fully. Remove and discard infested blooms; apply spinosad or neem oil; use sticky traps to monitor levels.