The proliferation of desert wildflowers this year has generated my keen interest in planting many in my own garden. So I contacted Boyce Thompson Southwestern Arboretum for more information. Copies of their materials are on file at the cooperative extension office. Here are some general guidelines offered by Barbara Mulford Franckowiak in her article, "Desert Wildflowers":
Since wildflowers do not transplant well, direct seeding is necessary. Also, the seeds need the soaking autumn and winter rains to germinate. So, do your planning and planting by early winter.
Method: Select a spot in full sun, preferably free of perennial weeds. Slightly rake or lightly cultivate the ground. Adding a little compost improves upon nature, but too much may result in a leafy, non-flowering plant. Mixing the seed with a little sand or potting mix plus sand makes the seed distribution easier. Cover with 1/4 inch of soil. If there is a chance the seeds will be disturbed by wildlife, then spread twigs, leaves, and/or chicken wire over the area. Water the newly planted seeds until the rains take over.
Some wildflowers suggested for the Southwest include sacred datura, bare stem larkspur, shepherds purse, and horehound.