Wildflowers like these at Catalina State Park may bloom well in the spring. 

Doug Kreutz / Arizona Daily Star

Deep-soaking rains across Southern Arizona over the weekend were a “triggering” event for a possibly bountiful wildflower bloom next spring.

“We got the requisite triggering rain to set dormant seeds of spring wildflowers, grasses and other plants into germination,” said George Montgomery, curator of botany at the Arizona-Sonora Desert Museum.

“If there are follow-up rains over the next few weeks, we should have a typical wildflower show,” Montgomery said. “With such a good trigger and exceptional follow-up rains, who knows? Maybe a very good show.”

Many parts of the Tucson metro area got 2 inches or more of rain from a weather system that parked over the area Friday and Saturday.

“We had 2.24 inches here at the Desert Museum” west of Tucson, Montgomery said. “The duration, from Friday evening into Saturday afternoon, allowed great infiltration of this first rain of the winter season.”


Meg Quinn, an environmental educator for Pima County and the author of books including “Wildflowers of the Desert Southwest,” said we’re off to a good start for a big bloom, but noted a prolonged dry spell could diminish the show.

“Annual desert wildflowers — including carpet-forming species such as Mexican gold poppy, owl clover and desert lupine — typically require a good soaking rain in October or November to trigger mass germination,” Quinn said. “Although the recent deluge provided plenty of precipitation at the right time of year, things can still go awry.”

One of the things that could go awry, she said, would result if steady rainfall fizzled to a drizzle.

“At least one good rainfall event of a half-inch to 1 inch per month is needed to keep the tender seedlings alive,” Quinn said. “A prolonged dry spell of six weeks or more could desiccate the young plants or cause stunted flowering, especially if temperatures are warm.”

Still, Quinn, like other wildflower lovers, is keeping her hopes up.

“Depending on the timing and amount of winter rain going forward, we could have a bonanza of spring wildflowers,” she said.

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