Tree Pro Grow Tubes have Tested the Best Tree Protector for Survival and Growth!
While all protectors stimulate vertical growth, excessive vertical growth is primarily a problem of the darker, twin walled tree tubes. Because they transmit less light, the tree will "concentrate" growth on the vertical in an effort to reach the light entering the top of the shelter. With lighter colored vented shelters such as Tree Pro and Miracle Tube, enough light enters the protector wall to stimulate diameter growth.
During a study lasting from 1996 to 2002, Purdue University of West Lafayette, Indiana, found the shelter with the lightest color; i.e., Tree Pro Tree Protector, produced a 35 percent improvement in diameter growth in Engelmann spruce seedlings over the shelter with the darkest color.
According to Dr. Hailu Sharew of the Maryland DNR, seedlings protected by brown protectors attained a height of 53.7 inches and a diameter of .462 inches after three growing seasons. The average Tree Pro seedling attained a height of 65.5 inches and a diameter of .646 inches. 37 percent improvement.
The average Miracle Tube seedling did even better than best of the five protectors studied. (Tree Pro Shelter was second best.) The average Miracle Tube seedling attained a height of over 74 inches and a diameter of .678 inches in that same period of time. 47 percent improvement.
According to a Study done by the Maryland Department of Natural Resources, Miracle Tube out grew the Competitors by an average of 16 inches, and more than twice as tall as unsheltered seedlings. They recommend using Miracle Tube to significantly increase height and diameter size of seedlings. In a study of Red Oak and White Oak by The Pennsylvania Bureau of Forestry Tree Pro out grew the competition by approximately 45 centimeters and had a higher survival rate.