Branching Out
Elm trees used for lesson on grafting
A hundred years ago, American Elm (Ulmus Americana) was one of the most commonly planted shade trees in the Eastern half of the US, including in Nebraska. It was prized for its lofty trunk and dense leafy canopy, as well as its tolerance to weather extremes and its rapid growth. In many cities, elm trees lined the streets and shaded the parks. However, the species was nearly wiped out due to a fungal infection called Dutch Elm Disease (DED) that swept across the country starting in the 1930s.
Due to its disease susceptibility, the Upper Big Blue Natural Resources District doesn’t sell American Elm through the annual conservation tree program, which provides low-cost, bulk tree seedlings each spring in species selected for best performance in this area. However, when McCool Junction resident Brad Morner reached out to the NRD about ordering elm trees for classroom use, District Forester Kyle Yrkoski was able to special order 25 elm seedlings.
Morner’s two sons, Alex and Aaron, are students in agriculture classes at McCool Junction High School. Morner asked their teacher, Dana Hall, if he could teach a lesson on tree grafting during a plant science class, as he used to operate a tree nursery. Grafting is a method of propagating trees that involves creating a wound in one plant and attaching another to it, allowing the plants' tissues to knit together to form something new.
Hall was enthusiastic about the idea. “It’s really great to have experts in different areas share their knowledge with students and expose them to different careers,” she said. “Any time I can have experts come in and share their experience with students, I think it’s a great thing.”
Morner and his wife, Patty, provided all the items necessary for the lesson, including silver maple cuttings to practice with. The couple showed students how to take a freshly sharpened grafting blade and notch two tree cuttings together so that their cambium layers align, then bind the stems with elastic and grafting tape. Morner explained that as the tree wounds heal, the two trees will grow together as one, the roots from one tree supporting the cutting from the other.
To have a successful tree graft, you must have genetically similar trees (you can’t grow apples on a pine tree, for example). On the elm rootstock ordered through the NRD from Bessey Nursery, the students grafted a cutting from a DED resistant elm tree in Waverly, Nebraska. As the grafted trees grow, they will be genetically identical to the Waverly tree.
Why not just grow the trees from seed? Planting from seed doesn’t guarantee that the desired traits will be carried on, Morner explained to students. Grafting is the only way to make sure that the new tree has the traits of the parent tree—in this case, DED resistance. Today, Morner farms full time, but still has a clear passion for trees. Alex and Aaron help on the farm and manage Morner Brothers Honey, maintaining hives in the McCool area.
Mercifully, there were few injuries and little blood spilled during tree grafting lesson, despite sharp knives in inexperienced hands. Students potted their grafted elm trees to take home and plant.
Looking for NRD tree seedlings to plant this spring? Time is running out! Reach out to the Upper Big Blue NRD to see what’s left in inventory in the tree cooler by calling 402-362-6601 by April 26.