Kyle Daniel, Nursery and Landscape Outreach Specialist, Department of Horticulture and Landscape Architecture
Production methods in container nurseries have evolved since the 1950’s as soldiers returned home and new housing was being built across the country. Beginning with metal cans (hence the name some nurserymen use the term ‘can’ when referring to a growing container) and moving to blow-molded or injected plastics, new technologies have increased production per unit and a higher quality crop. There are now growing containers of many materials, sizes, designs, and additions, such as copper sulfate to reduce root girdling and circling).
A common problem for container grown trees is an improper root system. Most species of trees have a large expanse of roots, thus growing them in a small confined area can produce many root deformations. Within a short amount of time (as soon as three weeks), roots can start to develop root deflections, which can lead to root deformations in the future (Figs. 1 and 2). New container technologies have been developed for a more sustainable root system that includes air pruning pots, fabric bags, compostable material, and others. This new technology, which attempts to address this problem is on the market, but much more research is needed. A proper root system is necessary for the long-term viability of a tree. That proper root system begins in the nursery and at a young growing stage, so the nursery industry is starting to become proactive in these endevors. This will insure, not only a reduction in transplant shock, but also the long-term benefits to the tree.