By Nora Palmatier
Tree Stewards have heard me brag about the huge oaks in my backyard, especially since the Quercus falcata became not only the Arlington County Champion but also a Specimen Tree, entered on the property deed and needing County permission to remove. It has a Diameter at Breast Height (DBH) of 60 inches, which means I can stretch out on the ground beside it with toes touching a buttress root while hands over my head can barely touch the opposite side buttress root. The fact that a Quercus alba (DBH 30 inches) shares the same mound and stretches almost as tall is another bragging right.
This year, the white oak is gorgeous and full. The southern red oak is, well, even a tree lover would call it scraggly, and quite a few large limbs show no greenery on the tips (Qf to the left in the photo above, Qa to the right). I think everyone on the Tree Steward list serve has read about the high incidence of oak decline and most likely guesses what the arborist from Bartlett Trees said. He commiserated with me and gave two choices:
- Remove the dead limbs (sheds, fences, play areas, and a house could all be considered “targets”), and treat the borers. No promise that one would not need to prune more limbs each year or how long tree would not be considered a risk. Given the height of tree and safety for climber, this would cost about the equivalent of a nice vacation for us.
- Remove the tree now at a cost of three times the one-year pruning and borer treatment.
I immediately swung into the denial part of the grief cycle and contacted experts who have taught us Tree Stewards. Eric Wiseman, Ph.D. Associate Professor of Urban Forestry, Virginia Tech, is director of the Big Trees Virginia program that keeps track of state champions. I emailed him asking if there was research proving that the largest champion trees took much longer to decay (and thus were safer) since they had such huge trunks. Nope.
“I do not have any specific research that I can direct you to on this topic. Although I don’t follow the literature on this topic real closely, I feel confident in stating that controlled studies of oak decline in urban settings is scarce, particularly when it comes to evaluating treatment response and recovery rates. Oak decline has been studied quite a bit in natural forest settings, but those studies mostly revolve around examining the causes of decline and describing its epidemiology, and don’t get into treatment because it is rarely feasible to treat ailing oaks in natural forests. And obviously the environmental context is completely different, so it’s hard to extrapolate to urban areas. When trees lose vitality, they lose their defenses against borers. It’s analogous to an elderly person becoming more susceptible to secondary infections when in poor health. Just like with the human, you have to control that secondary infection (the borers), but also treat the primary sources of poor health, which in this case may be soil and root health.”
He did suggest contacting Arborist Guy Meilleur with Historic Tree Care in Apex, NC, and the website filled me with hope! The Case Studies of Historic Tree Care had photos of trees bigger than my oak that were carefully preserved for decades. Guy Meilleur is also a great writer, so I spent hours perusing the site. Like most tree lovers, he knew how much my oak meant to me and provided information on rejuvenating the soil. He would not be up in Northern Virginia for several months, and he did refer to significant loss of red oaks and asked about “targets” around my oak, which made me rethink my optimism.
Extension Agent Kirsten Conrad also responded to my plea for assistance, but she offered no magic cure: “I’m happy to come by, but here’s my two cents and I doubt that it would change on site. As you know we saw crazy numbers of oaks fail last year of oak decline. The stresses on the trees lowered the trees’ ability to defend itself, and borers were found in large numbers in many of them. Yet the borers are not the cause of death or even of the tree’s decline. So, there is no question that they do actually cause some harm and primarily as the holes become entry sites for wood decay organisms. Also, if i thought that pruning would somehow invigorate the tree then yes, I would prefer that option, but I don’t think that pruning will do more than just extend the eventual removal of the whole tree. So ask about leaving a 15-18′ snag for wildlife and what would that cost.”
Virginia Department of Forestry Arborist Jim McGlone called after getting my anguished email. His response was the 60 inch DBH Quercus falcata was declining because it was 60 inches, meaning it had matured to its fullest after a long life. He referred to the session he does on tree physiology, which discusses the impact of stressors such as drought, flooding, crazy weather impacts the xylem, phloem, leaves’ stomata. and roots. It’s a complex system. This was a learning I did not want to hear, but it does bring us back to the basics: trees are living beings, and they do die.
I needed closure, so I did what we Tree Stewards recommend and contacted an expert arborist not connected with a tree service. Consulting Arborist Ed Milhous came out and did a high tech assessment — he tapped a rubber mallet all over the red oak’s trunk which resulted in a hollow, drum sound. Then, he tapped the white oak which gave a firm, solid thunk. The red oak was full of decay and rotten inside while the white was in good shape. He then stood back and examined the canopy, pointing out where dead branches started and those nearby with sparse leaves. Together we reviewed the surrounding neighbors’ yards with sheds, playground, fence, and patio all under large limbs. Should the entire tree fail, it had four houses it could impact, including a direct hit on our bedroom! The conversation turned to ways to minimize tree removal cost with options to leave a 20 foot snag, placing large limbs at the back of the property instead of hauling away, checking ability to salvage for local wood workers in such a tight space, and waiting till winter to minimize impact on the white oak and landscape.
I did not truly learn anything new, and the first arborist’s suggestion to remove is what we will do. I clearly went through the rage, denial, and bargaining to end at grudging acceptance. My new goal is to research and interview companies to ensure that the Quercus alba is not damaged during the removal of its long-time partner. I will keep you updated on the process.
Oh, and I still believe mature trees are a valuable asset to one’s landscape in most situations. But I have a greater appreciation for their becoming liabilities!