Eighteen species of woody landscape trees commonly produced in the southeastern United States were grown in 3.8 1 (# 1) plastic containers painted on the inside with cupric hydroxide (7% w/w) and untreated control containers. Plants were evaluated for copper toxicity symptoms, root circling and growth. No copper toxicity symptoms were observed. Root circling and deflection were completely controlled except for bald cypress and laurel oak. Yet for these two species, root circling was less in the copper-treated than control containers. Root circling was not controlled in the bottom of square containers designed to prevent root circling for a subset of six species. For a few species, treatment effects on plant growth were seen, though most would be commercially insignificant.
Florida Agricultural Research Experiment Stations Journal Series No. R-02423.
3Extension Agent IV, Hillsborough County Cooperative Extension Service, 5339 State Road 579, Seffner, FL 33584-3399