Garden Update
Kathleen Cue, Nebraska Extension Horticulture Educator
With September upon us, it’s time to think about tree planting. If tree selection is on your to do list, putting the effort and time into researching what trees to plant pays off in a tree canopy that nets long term benefits in shade, beauty, soil stabilization, and stormwater mitigation.
Start by taking an inventory of what is already there—not just what is in your yard but in the neighborhood as a whole. Being the sixth person on your block to plant the same tree in the yard means loss of significant tree cover when an insect or disease wipes them out. (Think of the emerald ash borer with ash trees.) Diversifying trees in a landscape lends resiliency and negates the need for treating every single tree when a species-specific problem strikes.
Next, seek the input from tree people. Not tree people who blog from their work site far away, but tree people from your region, who have experience in troubleshooting tree health issues and provide consultation for trees problems that have developed 5-10 years after trees are planted. Understanding what problems are commonly seen is information worth knowing when selecting a tree.
The final consideration is the mechanism for how the tree is grown out at the nursery—potted, B & B (balled and burlapped), grow bag, and bare root. Potted trees should be in a specialty pot that prevents roots from circling, which would require removal/disentangling before planting. B & B trees deliver larger trees but also have lost a considerable portion of their root system when dug by a hydraulic tree spade. Grow bags are made of a heavy-duty mesh fabric that allows roots to breathe and develop without circling inside the bag. Bare root trees, primarily available for purchase in the spring, saves considerable costs in transport because there isn’t the added weight of soil. All of these mechanisms for roots have advantages and disadvantages.
Don’t be afraid to purchase a small tree. “What is a fast-growing tree I can plant?” is a common question and too often results in planting the same trees over and over again. Small trees, having a more complete root system, don’t have to overcome root loss and girdling, sending energy into top growth, a huge benefit. The old belief to stay away from planting an oak because it is slow growing is no longer true when beginning with a small tree.
Many problems are actually created when trees are planted, so pay close attention to the root flare, the part of the tree’s anatomy where the trunk flares into a root system. If the flare isn’t visible above the soil line, the tree is too deep. Trees can be too deep within the pot, ball, or grow-bag themselves so be sure to determine where the flare is located on the tree and then plant so the flare is slightly above the soil line.
Looking for a good tree list? Start with the Nebraska Statewide Arboretum’s “Trees for Eastern Nebraska”: https://go.unl.edu/7iwr .
Photo Below: Honey Locust Tree
Go to Dodge County Horticulture web page for more gardening information.