A Different Way of Digging

by Ed Barnett

Master Gardeners are familiar with the three methods of digging and shipping woody ornamental plants to the nursery: balled and burlapped, bare-rooted, and container grown. There is a fourth method that is becoming increasingly popular with the retail nurseryman and also the consumer~ the root control bag.

There are disadvantages to the three traditional methods of shipping the bushes and trees. The roots of bare- rooted plants are often squeezed into the shipping tube in unnatural shapes, and care must be taken to spread the roots out into a more natural position. They must also be watered frequently, or the specimen will die. Container grown plant roots must often be cut from top to bottom to promote the regeneration of new root growth, as the roots are frequently encircling. In some cases, root girdling will occur. The weight of the balled and burlapped tree can be so great that it can be difficult to maneuver into the planting hole, and the burlap is sometimes treated with a substance that prevents it from rotting into the soil. The consumer must remove it or the roots may not be able to penetrate the canvas. Because about ninety-eight percent of the roots are pruned at digging time, the plant must devote much of its time to producing new roots before it can grow upwards and outwards. The wire baskets used to hold the ball in a tight sphere are almost impossible to remove, as they appear to be a heavy gauge metal. In exasperation, I have planted tree and basket. Later I learned in a Master Gardener class that the tree might die as it reaches maturity. The roots, as they expand in diameter, will be squeezed to death as they attempt to penetrate the tines of the cage.

The root control bag is not exactly new, having been around since 1980. The root control bag is a non-woven, non-biodegradable bag made of polypropylene and manufactured by a company called Root Control, Incorporated and a few other businesses. It resembles felt. The fabric appears to be about an inch thick and is malleable to different shapes to hold various sizes of trees and bushes. The bottom is made such that the roots hitting the plastic bottom are redirected laterally into the fabric side. Thus, easy digging is assured. At the wholesale nursery, the seedlings are planted into the root control bags in ordinary field soil. The roots are able to absorb nutrients from the soil, as the material is porous, allowing the uptake of water and nutrients. As the roots grow laterally, they strike the fuzzy inside of the fabric and do not circle, as they do with plastic containers. The roots penetrate the tough fabric but are prevented from expanding. Thus this fabric continually prunes the roots automatically and as a result the root tips lose their apical dominance. Plants grown in root control bags have calloused roots, a high concentration of carbohydrates in the roots, and fibrous feeder root development. These three conditions contribute to immediate new root generation once the plant is transplanted. By using the root control bag, eighty percent of the root structure is harvested with the plant.

The advantages to the wholesale businessman are many. There is no need to purchase expensive digging equipment and laborers need not be experienced. Many trees can be dug by hand in a matter of minutes. Because of the natural pruning of the ba& the digging season is greatly lengthened. In fact, some growers dig all year long. There is no need to use mechanical root pruning devices. Also, the ball size can be half the size of a balled and burlapped plant. As a result, the nurseryman experiences lower handling costs and transportation expenses. Hopefully, he is able to pass this savings onto the retail nurseryman and ultimately to the consumer.

Sometimes the plant can be shipped directly to the customer, or the tree can be finished off in a large container or box at the wholesale business, If the consumer receives a specimen, he must simply remove the bag by cutting it with shears or scissors. Most likely, you will receive a specimen with a large canopy and trunk caliper and a small root ball. The roots, while looking inadequate, will quickly reestablish in the soil of your garden, as long as it is watered sufficiently. The plant, in a sense, hits the ground running because of its superior root structure produced by the gentle and habitual root pruning of the root control bag.