Planting Systems for Improved Stands of Fall Planted Native Perennials

Reliable commercial seed production of native plants is needed to restore rangelands of the Intermountain West. Direct seeding of native range plants for seed production has been generally problematic, especially for certain species. Fall planting is important, because seed of many species requires a period of cold to break dormancy (vernalization). Loss of soil moisture, soil crusting, bird damage, and other factors hinder emergence of fall planted seed. In previous research, the complexity of testing single factors has impeded successful stand establishment. A research approach was used testing stand establishment systems consisting of multiple factors. This trial tested the effect of four system components on emergence of seed of six species surface planted in Fall 2010 and Fall 2011: 1) row cover as a protective barrier against soil desiccation and bird damage; 2) sawdust as a substitute for the protective effect of organic debris; 3) sand to help hold the seed in place; and 4) seed treatment for protection from seed decay and seedling loss to fungal pathogens. The treatments did not test all possible combinations of factors, but tested the combinations that might work together to provide adequate stand establishment. All treatment combinations also had rodent control, a drip tape irrigation system if necessary (not used), and distractions for birds. Excellent stands were achieved for problematic species. Averaged over the two years, row cover with seed treatment and sawdust improved emergence compared to no row cover with seed treatment and sawdust for Achnatherum thurberianum, Penstemon deustus, Heliomeris multiflora, and Balsamorhiza sagittata.  Row cover with seed treatment and sawdust improved emergence compared to no row cover with seed treatment and sawdust for Penstemon acuminatus only in 2011. Adding sawdust to row cover with seed treatment did not improve emergence for any species, but reduced emergence for Penstemon deustus. The effect of systems with and without seed treatment on emergence differed by year.  Adding seed treatment to row cover and sawdust did not improve emergence for any species and reduced emergence for three species in 2010. In 2011, adding seed treatment to row cover and sawdust improved emergence for three species. Precipitation in March, when emergence starts, was higher in 2011 (3 inches) than in 2010 (0.6 inches). Adding sand to row cover, seed treatment and sawdust did not improve emergence for any species.