It’s not giant asparagus: Nine-foot agave showing off at botany greenhouse

Stop outside the University of Washington botany greenhouse to see an agave plant that’s grown a 9-foot-plus flower spike and is about to bloom for the first time in 25 years.

The spike, currently looking like a giant stalk of asparagus, started growing in April from the agave that’s 3 feet wide and 30 inches tall. The plant, an Agave parryi that’s native to Arizona, New Mexico and northern Mexico, gets a single flower spike that can grow 10, 12 or even 18 feet, depending on which botany website one consults, said biology’s Doug Ewing, botany greenhouse manager.

Toward the end of last week, bright green clusters of buds started peeking out from bracts on the flower spike.

The plant should put on a good show for much of June, Ewing said. The flowers are expected to be bright yellow. Agaves can be pollinated by bats, moths and humming birds, and if this one is pollinated there will be fruit that dries into pecan-nut-shaped seed capsules.

Agaves can grow from seeds but also send out offshoots that can root and become new plants.

Ewing says the greenhouse staff is already growing several offshoots from this particular plant. That means they will have a replacement because after the stalk dies back, the base also withers and dies, having spent all its resources making the stalk, flowers and seeds.