Response of dogwood cultivars (Cornus florida ‘Barton's White’ and ‘Weaver's White’) to styrene lining and copper hydroxide coating of 10.3 liter (#3) black plastic containers was evaluated in 1993 and 1994. After the first growing season, dogwoods were either left in their original containers or repotted into untreated 23.3 liter (#7) containers. Copper hydroxide reduced root circling of both cultivars in containers; however, root dry weight of plants grown in copper-treated containers was reduced during the first season. Copper-treated containers resulted in less growth in height when plants were left in their original container during the second growing season and less trunk diameter growth of plants repotted into 23.3 liter (#7) containers. In the absence of copper, more surface root coverage and less surface root dieback occurred with plants grown in styrene-lined containers. Both cultivars grown the second season in their original styrene-lined containers had greater height increase than those in unlined containers. After being repotted into 23.3 liter (#7) containers, both cultivars originally grown in styrene-lined containers had greater trunk diameter growth than those in unlined containers.
Supported in part by The Horticultural Research Institute, 1250 I Street, N.W., Suite 500, Washington, DC; Griffin Corporation, Valdosta, GA; J. Frank Schmidt & Sons, Boring, OR; and Dart Container Corporation, Leola, PA.
2Graduate Research Assistant.