Saguaros could qualify as the superstars of the desert on the basis of their stately form alone โ€” but this week theyโ€™re adding a sort of โ€œcoup de bloomโ€ with their first brilliant white flowers of the season.

โ€œSome saguaros usually start blooming by mid-April, but not a whole lot of themโ€ this early in the year, said John Wiens, nursery horticulturist with the Arizona-Sonora Desert Museum, west of Tucson. โ€œLate April to May is when lots of them are blooming, and they can continue into the early part of June.โ€

A few of the prickly giants break the mold when it comes to flowering.

โ€œSaguaros can bloom at any month of the year,โ€ Wiens said.

Even in December and January?

โ€œYes,โ€ Wiens said. โ€œThereโ€™s always an oddball here and there.โ€

SAGUARO BLOOMS 101

Wiens and a Saguaro National Park visitor guide provided some intriguing saguaro flower facts.

โ€œAn individual bloom opens somewhere around dusk,โ€ Wiens said. โ€œIt stays until midmorning the next day, and then thatโ€™s it for that one flower,โ€ which wilts by afternoon.

According to the Saguaro Park guide, โ€œThe spectacle repeats itself night after night for about four weeks until as many as 100 flowers have bloomed on each saguaro.โ€

Flying animals pollinate saguaro flowers in the few hours when they are open.

Pollinators include white-winged doves, lesser long-nosed bats, honeybees and moths.

They become powdered with sticky pollen as they feed on the flowerโ€™s nectar. Then they travel from flower to flower, transporting pollen and fertilizing as they go.

โ€œBecause saguaros are night bloomers, they are perfectly co-evolved with nectar-feeding bats,โ€ Wiens said. โ€œThe white flowers are visible at night, and they have a kind of cantaloupe smell that bats find irresistible.โ€

Following the blooming season, saguaro fruit ripens in June and July. The Saguaro Park guide notes that the sugary pulp of each fruit contains as many as 2,000 seeds.


Become a #ThisIsTucson member! Your contribution helps our team bring you stories that keep you connected to the community. Become a member today.

Contact reporter Doug Kreutz at dkreutz@tucson.com or at 573-4192. On Twitter: @DouglasKreutz