Laserfiche WebLink
• If a seed mix is properly designed for a specific cite using native and adapted species, the <br />selected plant species should have the genetic capability to withstand the climatic and <br />environmental conditions that occur during the growing season. Typically, seeds will remain <br />dormant until soil moisture conditions allow germination and establishment The seeds of many <br />species adapted to arid and semi-azid regions may remain viable and lie dormant in the soil for <br />periods of 5 or more years (Schuman et al., 2001). Allowing reconstructed soils to lie fallow <br />before planting permanent seed mixtures may serve to improve seedling germination and <br />establishment, particularly during drought cycles. <br />TIMING OF SEEDING OPERATIONS <br />There are two generally accepted primazy periods for conducting planting operations on azid and <br />semi-arid rangelands, including a fall and a spring planting period. When possible and <br />practicable, seeding operations will be conducted during these two general periods. Fall and <br />spring have proven most successful for seedling germination and establishment for a vaziety of <br />environmental, biological and equipment operation reasons. These aze generally the best times of <br />the year for conducting planting operations because: <br />• Soil moisture content rechazges during winter dormancy prior to the growing <br />season, which supports germination and seedling growth adequate to achieve <br />establishment prior to the summer dormancy period; <br />• The ground is not frozen; <br />• Snow cover is not present; <br />• Higher soil moistures facilitate prepazation of a suitable seedbed; <br />• Spring and fall months normally receive precipitation in greater amounts that <br />promotes plant germination and establishment; and <br />• Heavy equipment use associated with revegetation methods and treatments can be <br />timed to avoid impacts to excessively wet or dry soils. <br />Fall and spring plantings generally experience optimum seedling germination and establishment. <br />Cool-season grasses normally grow during the spring and fall when soil moisture is good and <br />temperatures are relatively cool. After establishment, about 2/3 of acool-season grass species <br />growth occurs during spring and early summer, the other I/3 occurs during the late summer and <br />fall. Cool-season species generally go dormant or exhibit very low growth during the summer <br />period when precipitation patterns aze highly variable. <br />Warm-season grasses experience their primary growth during the late spring and summer, <br />generally being dependent upon warmer air temperatures, deeper soil moisture and summer <br />rainfall to promote their growth. Warm-season grasses generally tend to be deeper rooted than <br />their cool-season counter parts due to their reliance on subsoil moisture. <br />Physiological characteristics of the cool-season and warm-season grasses can be used to <br />influence their germination and establishment composition. Variations in timing of fall and <br />spring planting periods may be required to obtain desired vegetation cover results. For these <br />• Appendix G 6 06/28/02 <br />