The peak blooming season at Pinnacles is from March through  May, when over 80 percent of the monument’s plants are in bloom. Depending on rainfall and temperature, flowers can begin opening as early as January and continue into June or, in a really wet year, into July. Manzanita, milkmaids, shooting stars, and Indian warriors are the most common early bloomers in January and February. By March, bush poppies and buck brush are the dominant flowering shrubs, along with forbs such as California poppies, fiddleneck, peppergrass, filaree, fiesta flower, monkeyflower, and baby blue-eyes.

In April, most of the March-blooming species are still blossoming, and such species as Johnny-jump-ups, virgin's bower, gilia, suncups, chia, black sage, pitcher sage, larkspur, and bush lupine have joined the spectacular display. A few early blooming species may still be seen in May, but center stage will be occupied by species that enjoy hotter, drier weather, such as chamise, buckwheat, clarkias, orchids, penstemons, and roses. Though late-blooming species may still be seen in early June of wet or cool years, by mid-June or early July, summer sets in and few blossoms are to be found.