What's eating my hoopsii blue spruce?

Hoopsii Blue Spruce, prized for its intense silver-blue color, is vulnerable to the same pests as other Picea pungens cultivars. Spruce spider mites are the most damaging, often dulling the ornamental blue foliage. Cooley spruce gall adelgid, white pine weevil, and spruce aphids round out the main threats in both the US and UK.

Stippled, yellow-bronze needles and webbing; color dulls noticeably; interior needles cast prematurely. Apply horticultural oil before bud break; insecticidal soap mid-summer; avoid drought stress which triggers rapid mite population growth.

Cone-like galls at branch tips each spring; infested tips die and leave visible stubs. Prune galls before opening; apply dormant oil annually in early spring.

Leader wilts suddenly in late spring; resin-soaked galleries under the bark of the top section. Prune leader well below galleries; destroy prunings; apply preventive insecticide to the leader in early spring if weevil pressure is known.

Sudden heavy needle drop in late winter to spring; affected needles yellowed before falling. Spray with insecticidal soap or neem oil when detected; a forceful water spray dislodges colonies; avoid nitrogen-heavy feeding that promotes soft growth.