Pot-in-Pot System for Caliper Trees and Shrubs

Kyle Daniel, Commercial Nursery and Landscape Outreach Specialist, Department of Horticulture and Landscape Architecture

Pot-in-pot production in ornamental nurseries can be an effective solution for some growers. The benefits of growing caliper trees and shrubs in containers, without some of the drawbacks, are realized with a pot-in-pot system. There are four major components to a pot-in-pot production system, which include: permanent container (socket pot), production container (insert pot), drainage, and irrigation. Due to these factors, there is significant installation cost. Some of the advantages to this system include: year-round shipping, lighter weight shipping (as opposed to field dug trees), insulated root zone from heat and cold damage, more control of root zone moisture and fertility, decreased production time, reduction of soil loss, and no container tipping. The disadvantages include: high installation costs, proper drainage, limited flexibility in spacing, and weed control issues. According to the per acre budget estimates for red maples in 2012, from the University of Kentucky, the return above annual costs the year after installation is $10,368. These installation photos are the beginnings of the new production system developed by the Purdue Arboretum at Meigs Horticultural Research Farm, just south of Lafayette.

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