Spring garden pest tips circulating

Gardeners are swapping low-tox pest fixes this spring, from reflective foil around plants to weekly scouting reports and kitchen-cupboard slug traps. (mortonarb.org) The Morton Arboretum’s Plant Health Care Report resumed for the 2026 season on April 3, with a growing-degree-day update posted April 10. The weekly report tracks northeastern Illinois pests, rainfall, soil temperatures and “indicator plants” that signal when specific insects are likely to emerge. (mortonarb.org 1) (mortonarb.org 2) On April 10, the arboretum reported 89 accumulated growing degree days at Lisle, Illinois, compared with a historical average of 0 for that date. The same bulletin listed viburnum leaf beetle among insects that may emerge soon at about 100 growing degree days. (mortonarb.org) Growing degree days are a heat tally gardeners use like a seasonal stopwatch: insects and plants reach each life stage after enough warmth accumulates. The arboretum says its report pairs that tally with bloom timing and management tips so gardeners can check for pests before damage spreads. (mortonarb.org 1) (mortonarb.org 2) The foil advice rests on an older pest-control idea called reflective mulch. University of California integrated pest management guidance says reflective mulches can disrupt aphids and other flying pests, especially early in the season when plants are still small. (ipm.ucanr.edu) Cornell’s integrated pest management notes say aluminum and other reflective films have reduced damage from aphids, whiteflies and other pests in crop trials. Utah State University Extension also says reflective mulches can make it harder for winged aphids to find vegetable plants. (cornell.edu) (usu.edu) Slug advice circulating alongside the foil trick matches extension recommendations on moisture and traps. University of Minnesota Extension says slugs thrive in cool, moist shade, while Oregon State University Extension says beer traps can attract and drown them if the container is set with the opening slightly above ground. (extension.umn.edu) (oregonstate.edu) Squirrel deterrent tips are less settled, but extension guidance leans toward barriers and repeated repellents over one-time fixes. Colorado State University Extension recommends burlap and staples to protect bulbs, and Ask Extension says capsaicin-based hot pepper repellents can help but must be reapplied after rain. (extension.colostate.edu) (askextension.org) The common thread is timing. Reflective mulch works best while plants are small, slug controls work best before populations build in damp beds, and the arboretum’s weekly April reports are built to tell gardeners what to watch for next. (ipm.ucanr.edu) (extension.umn.edu) (mortonarb.org)