What's eating my san jose hesper palm?

San Jose Hesper Palm is a drought-tolerant Baja California native grown as a landscape palm in warm dry climates. It is most commonly affected by scale insects and palm aphids on the foliage, and by red palm weevil in regions where this invasive pest is present. Spider mites can attack during prolonged drought. Its xerophytic nature reduces fungal and gnat issues.

Encrusted armoured scales on petioles and leaf undersides; progressive frond yellowing, stunted growth, and sooty mould. Horticultural oil spray in spring and early summer; manual removal with soapy brush for accessible fronds. Imidacloprid drench for established infestations.

Larvae bore through the crown and upper trunk causing internal rot; first visible sign is the spear leaf collapsing. Preventive systemic insecticide applications in affected areas (California, Canary Islands, Mediterranean). Monitor with pheromone traps; notify authorities if suspected.

Flat dark colonies on young fronds; sooty mould on honeydew reduces photosynthesis. Apply insecticidal soap or neem oil spray; water jets to dislodge colonies. Encourage natural predators in the landscape.

Pale, dusty stippling on leaflets and fine webbing on undersides, especially during hot, dry desert-climate summers. Deep-water the root zone to reduce drought stress. Apply neem oil or insecticidal soap spray in the cool of the morning every 7–10 days.