Four planting depths and two time intervals (1 or 2 years) between transplanting and initial year of harvest of asparagus (Asparagus officinalis L.) yield were compared for 4 years. Spear emergence and initial spring harvest date were delayed and susceptibility to spring frost injury was decreased with increasing planting depth (from 5.0 to 20.0 cm). Over years, crown depth increased for the shallowest planting and decreased for the deepest planting. Harvesting after 1 year vs. 2 years from planting reduced yield. There were no significant interactions between year of initial harvest and depth of planting.
Wildflowers/native plants are increasingly being used in landscapes, especially in low maintenance areas. Buffalograss is also receiving attention as a low maintenance grass. Establishing wildflowers in buffalograss would be useful in sites where mowing occurred only once in the fall, such as with minimeadows. Four experiments were conducted to study the establishment of wildflowers in buffalograss. Survival of wildflowers after one year was 88% when wildflowers were planted as greenhouse grown transplants and buffalograss plugged in 2 weeks later, 67% when one-year-old field grown wildflowers were transplanted into buffalograss plugged at the same time and 48% when greenhouse grown wildflowers were transplanted into established buffalograss. Establishment of wildflowers overseeded into established buffalograss sod was very low. There were significant differences in wildflower survival within each study. Species which performed well in buffalograss included Leadplant, Blue Fax, Purple Prairie Clover, Little Bluestem and Stiff Goldenrod.
Penstemon, a U.S. native plant/wildflower, is increasing in use as a landscape plant. Penstemon species are commonly propagated by seeds. However, species vary greatly in percent seed germination,
Seeds from eight sources of Penstemon germplasm were given cold moist stratification periods of either 0, 2, 4, 6, 8 or 10 weeks. One-half of the seed for each treatment was scarified with sandpaper. The study was repeated twice, once in 1989 and once in 1990.
Seed germination varied with species, and with the length of stratification. Greatest germination occurred at the 6, 8 and 10 week periods and the lowest germination occurred with no stratification. There were also differences between species in percent germination, Average percent germination was highest for P. gracilis and lowest for P. haydenii There was a significant species × stratification interaction, Seed scarification did not influence germination as much as seed stratification in these studies
Studies were conducted to evaluate the effect of stratification and seed age on percent seedling emergence of Penstemon. Emergence differences occurred between the eight Penstemon selections, as well as between seed stratification treatments and seed age. Seed stratification significantly increased emergence. Emergence varied from 0% with 1-year-old seed of Penstemon digitalis with no stratification, to 72.8% emergence with 2-year-old seed of P. angustifolius with 10 weeks of stratification. Seedlings from 3- to 4-year-old seed generally emerged as well as or better than with 1- and 2-year-old seed. Percent emergence varied significantly with stratification, seed age, and species. Some emergence occurred with species from seed up to 10 years old.