Many trees suffer from transplant shock after being dug from the nursery and put into containers to be sold at the garden center. Often less than 5 percent of the original roots survive the move. The shoots can't get enough water from the diminished root system and consequently a mortality rate of 30 to 50 percent is common the first year after transplanting.
In order to accelerate new root growth on transplanted trees (and hopefully reduce mortality), researchers at the Bartlett Tree Research Laboratory in England have tried adding sugar water to the tree root system. In trees that have a low survival rate, such as birch, watering with a sugar-water solution increased root growth and survival rates.
Researchers found the best root growth rates were achieved when they applied 10 ounces of sucrose (table sugar) per gallon of water and drenched the newly transplanted trees at a rate of 0.4 gallons per tree each week for 4 weeks, starting two weeks after bud break. The trees in the study were less than 2 inches in diameter. Further research is planned to see if sugar water also will increase survival rates of larger diameter trees as well.
For more information on this research go to: Journal of Arboriculture.