A few weeks back, I accompanied a former student of mine, now a professional forester, to a planting site on his company land to inspect both seedling and planting quality. As we arrived on the tract that had been site prepared for its new forest, I noticed something that deeply concerned me.
One of the planters had separated himself from the rest of the crew and was filling his planting bag for another run. He was down on both knees with his hoedad planting tool firmly secured between them. It appeared that he was taking the seedlings from the box and then holding them on both ends. I could see him making an up and down motion with his arms and I instantly knew what was going on.
I got out of my truck and headed in his direction. The tree planter immediately started trying to hide his actions, but the pile of cut roots next to him was too much to cover. I caught him prepping his bag of work for easy planting and it was obvious that he did not understand, or care, about the consequences of his actions. Upon further investigation of the tract, several piles of roots were discovered by the forester and me. It is an age old problem as old as artificial regeneration itself. Tree planters, in order to make planting easy, will cut, chop, bite or chew off roots to make for easy insertion into the planting slit, thereby producing a damaged seedling with disproportionate shoot/root ratio and a major loss of absorbent root tips.
Your seedlings arrive from our nurseries with the perfect shoot/root ratio.
Seedlings need a proper root system for survival over winter months.
The shoot/root ratio of a Grade 1 seedling is approximately 2:1. In other words, a seedling with 10 inches of shoot above the root collar should have 5 inches of roots. The SuperTree Nursery managers take special precaution and steps to achieve this perfect ratio. As the seedlings grow in the nursery beds, they are provided with the water and nutrients to keep them from being stressed before winter lifting. During the late growing season going into fall, the seedlings are top pruned, undercut and laterally pruned to ensure a perfect shoot/root ratio. These steps are performed in the nursery beds while the seedlings have ample time to recover from the lacerations before they experience the shock of being lifted and out-planted to a new location. These steps render the need of any pruning in the field by tree planters unnecessary and damaging. No matter how much we strive for the perfect shoot/root ratio of a Grade 1 seedling at the nursery, it is all for naught when the roots are severed from the young seedling, and therefore reduces their survival and vigor. The seedlings have already recovered from being pruned in the nursery beds and are then forced to recover again after they come out of dormancy in the spring.
Most plants have a dormancy period at some time during the calendar year. For southern pines, this time is during the winter months or after they have received enough chilling hours at the nursery. This is why pine and hardwood seedlings are planted during this time. This helps keep from shocking or stressing it any more than the lifting and planting process already has. As a plant goes into dormancy, it sends all of its nutrients down into the roots (fall) for survival over the winter months and then for breaking dormancy in the spring. This time period can be viewed as a type of hibernation for the plant. If the roots are cut off just prior to planting by an inexperienced planter, he or she is thereby removing part of that seedling’s stored nutrient reserve.
In a 2009 publication by the North Carolina Forest Service, the author simply states to not prune or cut-off any parts of the seedling – especially its roots. Likewise, in a Natural Resources Conservation Service (NRCS) publication, entitled Seedling Planting Guidelines,the author states that the roots should not be pruned unless the laterals are 5 inches or longer and then only by a sharp instrument. Most planters that prune the roots use either a dibble or hoedad, both of which have a blunt end due to repeated use. I have even had personal communication with a forester that has witnessed planters biting the roots off. Whichever of these instruments used, they will not qualify as sharp.
Keep the protectant gel to reduce stress on roots.
Root pruning by tree planters severely reduces the number of fine roots and root tips, which are the majority water and nutrient absorption sites on roots. One other bad behavior to prevent that can be damaging to these tender tissues is when planters try to knock off the protectant gel on the roots by slapping or stripping root systems through their hands. This starch-water based gel is sprayed onto the roots just before being packaged and is applied to reduce water stress on seedlings after planting but before new roots are formed.
Protect your investment by proper supervision.
Whether you are the planting contractor or the landowner, you should be aware that this can happen without proper supervision. It is common knowledge that when you damage a plant, you are therefore stressing it unnecessarily. Seedlings are not easily produced in the nursery and therefore are not cheap for the consumer. You should want to give them every advantage for survival and growth. Cutting or ripping roots off will always stress the seedling, thus costing the landowner his or her investment in growth, vigor, and even seedling survival.