Begonia · Perennial
Powdery mildew: Improve air circulation and treat with a suitable fungicide or bicarbonate spray.
Slugs and snails: Use physical barriers, copper tape, or approved slug pellets to protect foliage.
Root rot: Ensure pots have drainage holes and allow compost to dry slightly between waterings.
Aphids: Squash by hand or spray with a strong jet of water or insecticidal soap.
Vine weevil: Apply biological nematodes to the compost in late summer or autumn.