Seeding dates and field establishment of ten southwestern desert wildflower species

The effects of planting date were evaluated on field establishment and flowering of ten southwestern wildflower species combined in a mix. Species tested include Baileya multiradiata, Castilleja lanata, Eschscholtzia californica, Eschscholtzia mexicana, Gaillardia pulchellum, Lesquerella gordonii, Lupinus sparsiflorus, Orthocarpus purpurascens, Penstemon eatonii, and Phacelia campanularia. Seeds of all species were combined in a mix and directly seeded into field plots. All species are native to the southwestern deserts of the United States. Treatments consisted of five planting dates, starting September 30, 1987 and continuing through November 30, 1987, with treatments planted at two week intervals during the ten week period. There were significant differences in both plant stand and flowering between planting dates. The October 15 planting had the optimum plant stand with regard to the largest spectrum of species represented by desirable numbers. Flowering was most pronounced in the September 30 and October 15 plantings