UNITED STATES—Superbloom is brief for two main reasons. It involves native species that know to bloom quickly before arid weather of summer. Also, wildflowers in the wild receive no irrigation to sustain bloom through arid weather. With irrigation, some of such species are capable of prolonging bloom. A few can disperse seed for subsequent generations to bloom later.

That is why California poppy blooms for a longer season within home gardens. It easily performs through much of summer with irrigation. Also, with irrigation, it might regenerate to bloom for autumn after summer dormancy. Seed from earlier spring bloom might grow to also bloom for autumn. Some godetias and lupines perform similarly within cultivation.

Most species within home gardens are exotic though. In other words, they are not native. Those that are native to a similar Mediterranean climate respond similarly to cultivation. Generally, some from desert climates do so also, although many dislike extra irrigation. The majority of exotic species actually rely on some degree of cultivation and irrigation.

Most vegetation within home gardens is not native to Mediterranean climates.

Such species are native to climates with cooler and less arid weather through summer. Rainfall here is too limited to winter to sustain them through summer. Minimal humidity and warmth increase the need for moisture while it is least available. Cooling summer breezes actually accelerate desiccation. Arid weather certainly has its disadvantages.

As spring relinquishes to warmer and drier summer, irrigation becomes more important. Frequency and duration of automated irrigation must adjust to increasingly arid weather. Shallow root systems, such as those of turf grass lawns, require more frequent irrigation. Deep root systems, such as those of maturing trees, require more voluminous irrigation.

However, irrigation should not be so excessive that soil remains saturated. Many mature trees and shrubs need none at all. Some receive enough from what adjacent vegetation does not consume. Some are satisfied with only occasional irrigation. Turf and annuals require the most frequent irrigation. Yet, even they can rot if their soil is always saturated. Calibration of irrigation requires diligence.

Highlight: Punchbowl Godetia

All 41 species of Clarkia that are native to North America are native to California. Punchbowl godetia, Clarkia bottae, inhabits almost all counties of Southern California. It is absent only from Imperial County. It also inhabits Monterey and San Benito Counties. Its name may allude to its floral shape, or its bloom in Devil’s Punchbowl near Valyermo.

Punchbowl godetia is an ephemeral annual that blooms briefly for spring. Bloom is early in some regions but late in other regions. Also, its schedule is variably from year to year. Because it does not transplant easily, it is rarely available from nurseries. It grows better from seed, which is available online. Within favorable situations, it self-sows after bloom.

Bloom is delicate and airy, on limber and lightly foliated stems less than three feet high. Individual flowers are barely an inch wide. Floral color is slightly purplish pink with white centers and tiny red spots. It is variable though, so might be a bit more purplish or lighter pink. Leaves are very narrow. New seedlings do not compete well with other vegetation.

Tony Tomeo can be contacted at tonytomeo.com.