Vegetative Propagation of American Elm (Ulmus Americana) Varieties from Softwood Cuttings

Softwood cuttings of American elm varieties ‘Jefferson’, ‘New Harmony’, ‘Princeton’, ‘R18-2’, ‘Valley Forge’, and a tissue-cultured non-transformed control clone (BP-NT) were rooted using three different treatments to determine which method would be most suitable for small-scale propagation. The treatments included aeroponic chambers, an intermittent-mist bench in a greenhouse, and Grodan rootplugs soaked in a nutrient solution. The rootplug treatment had the highest percentage of rooted shoots (44%) followed by the intermittent-mist bench treatment (20%) and lastly by the aeroponics chambers (10%). The rooted cuttings from the rootplug treatment also looked substantially healthier and had more fresh growth four weeks after potting than the other two treatments. The Grodan rootplug treatment is recommended, but additional testing can be useful to improve the overall rooting percentage.