Question: Why did the big old historic kiawe tree at the Halekulani Hotel fall over? Could it be saved? Could they plant a new one if not?

Answer: Trees in urban settings need maintenance. As arborists we recommend an annual light pruning to remove dead wood, reduce the weight of over-heavy branches and balance the growth. We have recently had some very wet summers, so many of our valuable trees are in need of a good summer trimming.

Yes, a new one could be planted. We need to grow more thornless kiawe. Kiawe, a species of mesquite, is in the bean family, Fabaceae, and they are easy to grow and they grow rapidly, if given good horticultural and arboricultural care.

If you collect seeds from a thornless kiawe tree and grow them, about 10 percent of those keiki trees will be thornless, too. You select and grow the ones without any thorns and they will grow up to be trees with no mean thorns to poke your feet.

(Local keiki know, those thorns are mean! They penetrate even heavily calloused bare feet and even your zoris if the rubber is not too thick! The tips of the thorns break off, you get a foot infection, your mom tries to dig it out with a sterilized sewing needle, you have to go to the doctor and you learn to watch out for and avoid those kuku! Just sayin’!)

These big old kiawe tend to be thornless. Maybe they put their energy into growth rather than thorns. We have lost many over the years and do need to replant. This is true in Kapiolani Park, at the University of Hawaii at Manoa, at the Hale Koa Hotel and at the Halekulani. They are a great tree for our urban forests and public parks. Any large space can be a good place to grow thornless kiawe trees.

Kiawe are drought- and salt-tolerant. They are useful and produce edible seed pods. Flour can be made from the pods (and it’s non-GMO and gluten free!).

On Friday, a Halekulani spokeswoman said the hotel is still trying to figure out what prompted the tree to fall.

But I spoke with Steve Nimz, head arborist for the Halekulani trees. Nimz has nurtured and trained many of us here in Hawaii who are now certified arborists.

The Halekulani tree fell parallel to a nearby hedge — perfectly positioned, Nimz said.

“I could not have dropped it better (with pruning and cranes) than it did itself,” he said. “It fell in the Ewa direction. It fell in the night. Nobody got hurt, it could not have come down in a better way even if planned and engineered.”

Just as with old trees in Japan that are revered and cared for, this tree can be professionally nurtured for future growth, Nimz said. A low branch had to be cut back, but in doing so, workers created a place where guests can sit for “the perfect picture,” Nimz said.

“It’s good to leave it on for now, let it sprout and regrow,” Nimz said. “We made a mound of soil around it, and recommend planting a new tree in back to graft onto it later.”

Nimz is looking for a 6-inch-diameter thornless kiawe seedling for the site if any of you akamai growers have one.

Nimz continued to say that “one piece of the trunk sticks up on top like a dolphin or shark’s fin. It’s pretty neat. We could cut it off for symmetry.” But he won’t, at least not yet. As arborists, we don’t cut something just to cut it — because we can’t paste it back. Every living, photosynthesizing, green, leafy bit of the tree is making food for the tree, including the roots. Because of the way it fell, there was significant root damage and letting the tree heal will allow it to regrow those roots.

There are lots of arborist options to preserve this tree for our future. It’s solid and safe, too. It’s worth the effort to let it grow again in its new form. And, again, let’s all think about growing and planting more thornless kiawe trees.

Heidi Bornhorst is a sustainable landscape consultant specializing in native, xeric and edible gardens. Reach her at heidibornhorst@gmail.com.