Ag Progress Days: Advice from the woods
by Stephen Wagner
Scott Weikert on Penn State Extension began his webinar during Pennsylvania’s Ag Progress Days by introducing his panel: Sarah Wurzbacher, forestry Extension educator; Allyson Muth, Department of Ecosystems and Management at Penn State University Park; Art Gover, Extension specialist based at University Park dealing primarily with invasive species and ventilation management; Margaret Brittingham, wildlife specialist at University Park; Calvin Norman, forest and wildlife Extension educator in Blair County; and others with forestry expertise.
“With the spotted lanternfly being a big issue in some parts of the state, what is the recommended way to control tree of heaven [to keep it] from re-sprouting?” Weikert asked. “It’s a big issue.”
Gover answered, “I think one of the key things about tree of heaven is to remember it’s what we would call a colonial or suckering species … What you need to manage is not what you see above ground, but the root system. The way you do that best is by working late in the growing season up until time of fall leaf coloration. The most effective means to do that is going to be using systemic herbicides. You can apply them to the foliage on smaller plants or to the stems of larger plants. One of the things we would stress is that you need to leave that tree largely intact.”
“While we think about the spotted lanternfly being closely linked to tree of heaven, they’re finding they can use other hosts,” Brittingham added. “Just getting rid of the tree of heaven won’t necessarily solve that issue. But they’re doing some really interesting work here looking at whether the spotted lanternfly itself is bad-tasting to predators – if it gets those toxins from eating the tree of heaven where it might be more palatable to other birds and other animals and prey.”
“I’ve heard there is a disease affecting American beech,” the moderator chimed in. “Can you describe what it looks like and how to care for the tree in case of infection? I have a number of them on my property, both mature and saplings.”
Wurtzbacher answered, “This disease has been in the northwestern part of the state for a few years now, but we are starting to see it become more aggressive. It’s called beech leaf disease. You may already have heard of beech bark disease, which has been around for awhile.” With beech leaf, “you don’t really see evidence of an insect or anything. It’s caused by a nematode.” This has only been recently established – “that’s how new this issue is,” Wurtzbacher said. “Right now there are no clear treatments that are suitable. The best thing you can do is to monitor it.” This case in question was in Monroe County, the northeastern part of the state.
The next question queried, “What can we do to save our ash trees that have not already succumbed to the emerald ash borer?”
Gover responded owners can treat ash trees to protect them. The insecticide to use, Dynotefuran, is effective. “It’s simple to apply; you can apply it right to the stem,” he said. A basal bark herbicide treatment is aimed at saving the tree rather than making the borer go away. “It’s an annual treatment. The last time I was in a room full of people who knew a lot more about emerald ash borer than I did, there even seemed to be an end point to it. It was not like ‘Okay, it’s a wave, and as the wave keeps going farther away from us our trees will be safe again.’ The consensus was ‘No, it’s here.’ And when the ash trees that emerge behind that original destructive wave start reaching diameters of about an inch, they’re going to become susceptible as well.”
Another webinar participant asked what shrubs and trees to plant to bring in songbirds.
Brittingham replied, “There’s such a diversity of species. Oak is a great one if you have no forest or canopy trees. Have some conifers – hemlock in particular. Serviceberry trees (or shadbush) are great for fall migrants coming in and getting those berries.”
Oak wilt is a problem newly imported to this country, and Norman explained it. “It drifted north to us from Mexico,” he said. “When it gets into oak trees, it kills them slowly from the top down. You will know when your oak has it. Mainly, it attacks red oaks, but it can also attack chestnut oaks and white oaks.” According to Michigan State University Extension, “Oak wilt is fatal for all the species in the red oak group (those oaks with pointy-tipped leaves). The white oak group is less vulnerable (those oaks with round-tipped leaves). Rapid wilting and loss of leaves begins at the top of the tree. The entire tree dies within a few weeks.”
“It can be a healthy red oak and in two months it’s done,” Norman continued. “What you do with an infected oak is take down all the oaks within an infected buffer, based on the size of the infected tree, and cut all the roots around that infected tree to make sure none of the surrounding trees can get infected.”
Muth was called on to offer a few pointers on estate planning and legacy planning.
“A lot of the studies we’ve done with landowners indicate that they really want the land to stay in their families. This involves things like making decisions about what you will allow to happen on your property, how you feel about potential subdivision or development, and do you want it to stay intact?” she said. “Family communication is a huge part of this: making sure your beneficiaries are on the same page, if you’re engaged in conservation organizations, and land conservancies who can help you out.”