City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: https://read.dmtmag.com/i/94460
people will hopefully start to use this technology to grow trees in paved areas while also capturing stormwater. We also want to explore grading water runoff toward planting wells/pits and other ways to maximize the water to our street trees in these hot, dry summers. Transplanting research? NB: The nursery industry is really interested in Missouri gravel beds, which use pea gravel and allow growers to dig up bare root trees in leaf in summer, thereby extending their sales period for bare root trees. If city foresters could successfully transplant bare root in summer—extending the season of transplanting—that is a win for them, too. We've just completed our first year of a study looking at differences among species grown with this method. It's looking like trees that are hard to transplant are not less so when grown with the Missouri gravel bed method. This has led to an exploration of why, physiologically, some trees are harder to transplant than others. No one has really figured it out yet, except to say that it seems to have something to do with cavitation, or bubble for- mation in the xylem. More cavitation, less water uptake. Bur oak (Quercus macrocarpa) has more cavitation, and is harder to successfully transplant, than swamp white oak (Q. bicolor). Once we get a better understanding of the problem, how could we reduce cavitation? That's where the real-world application comes in. Stay tuned. Another interesting finding from this gravel bed study is that when it comes to difficult-to-transplant species, a smaller caliper size will be more successful. But easy- to-transplant species did ok in all caliper sizes. So like with white oak (Q. alba), plant the smallest size caliper you can, but with swamp white oak, you can get away with a larger caliper. Of course all of these studies assume best horticultural practices. For instance, you can't put trees in structural soil and then walk away and never water the tree. With new technology, you still have to bring the good plant practices along. Work with Municipalities? Shallow maple root growth under sod 22 NB: In Ithaca we are doing a study that I've affection- ately nicknamed "The Duh Project," that seems very basic, but I think will be quite helpful to municipal for- estry programs. How can you get homeowners to water newly planted trees, and will that participation make the difference in that first critical year after transplanting? We launched an educational program asking homeown- ers to fill tree irrigation bags and then we surveyed them to find out what the barriers to watering are. For the newly transplanted trees, half of them were in front of homes where we asked homeowners to help, and the other half were not, for a control. And for those trees associated with homeowners that were asked to City Trees