This is the second in what will be an ongoing series of posts on the effectiveness of tree tubes on American chestnut trees. To find the others, type chestnuts into the search bar.
A private landowner and American chestnut enthusiast in Mississippi purchased some 100% American chestnut seed last winter, and sowed the seeds in root pruning pots, grew them into 12 to 18 inch seedlings, and the planted them on his property.
While the seeds were getting started he researched tree tubes, knowing that upon planting his seedlings would immediately be subject to heavy deer pressure. He contacted experts with the various chestnut restoration organizations for advice. He was universally told that 4ft and 5ft tree tubes don't work well with American chestnuts. The recommended method of establishment was either to use a 2ft tree tube (for rodent protection and initial moisture stress reduction) coupled with a wire cage for deer browse protection.
As we have discussed the basis of this recommendation was the poor results experienced by chestnut growers 15 to 20 years ago with the old, unvented, small diameter tree tubes sold at that time. A 'corkscrew' or spiral growth habit of American chestnuts growing in tree tubes was a complaint back then, as was winter injury or die-back.
This gentlemen also discussed the issue with reputable sellers of today's vented tree tubes, and of course got a completely different story; he was told how the problems cited by chestnut experts harken back to earlier tree tube designs, and that results on chestnut with the vented tubes sold for the last 10 years have been excellent.
It was the typical conundrum for a private landowner and hobbyist: Ask 10 foresters for advice and get 24 different - and often completely conflicting - answers. Who to believe? Luckily, this landowner did what so many other dedicated tree planters have done: He didn't believe anyone, and put both methods to the test.
The upshot after nearly one full growing season: "Tree tubes for American chestnuts should be 5 foot and trees should be above the tubes by August. I really like the way the seem to help manage moisture."
Asked about spiraling growth of American chestnuts in tree tubes he wrote, "The spiraling wasn't significant and now the trees have emerged straight as an arrow."
The trees grown in 3ft tree tubes within wire cages also did well, but...
1) Aren't nearly as tall as those grown in 5ft tree tubes.
2) The wire cages for deer browse protection are an unnecessary added hassle and expense as compared to using the 5ft tree tubes which provide increased survival, faster height growth and deer browse protection.
Results like these show why a sea change among American chestnut enthusiasts.
The "old" recommendation of using a 2 or 3ft tree tube along with a wire mesh enclosure for deer browse protection was based on a recognition of the effectiveness of tree tubes for rodent protection and increased seedling survival rates, but were also based on the negative results experienced when using the old unvented 4ft and 5ft tree tubes.
American chestnut planters using the newer vented tree tubes are seeing excellent results - and tree tubes are now fulfilling their promise as an indispensable tool in the monumental effort to restore the American chestnut to its rightful place in our Eastern hardwood forests.