In Honolulu gardens, we have trees grown from the world's oldest cultivated tree.

It was under a bo tree in India that Siddhartha Gautama — better known as the Buddha — became enlightened. Pieces of that tree were propagated and carefully planted in significant places.

One cutting was taken to Anuradhapura, Sri Lanka, in 288 B.C. It is the oldest existing cultivated tree that we know of.

In the 1930s, Hawai'i's Mary Mikihala Robinson Foster, who founded Foster Botanical Garden, donated money to monks in Sri Lanka to build a hospital (it still bears her name). The grateful monks gave Foster a small plant, propagated from the ancient bo tree. She, in turn, planted it in her garden and nurtured it well. Today you can see the large gorgeous tree growing just inside the entrance of Foster Botanical Garden.

The bo is a shade tree that needs a lot of space and good landscape planning to grow to its full majesty and beauty. You don't want to stuff this big ficus into a tiny cutout in the cement or tucked next to a building or parking lot.

Many cultures revere and cherish this tree. Bo or bodhi — Ficus religiosa — trees are important in Buddhist and Hindu traditions.

The bo leaf is striking with a curved "tail." Like our native 'olapa or a Mainland quaking aspen, the leaves dance to a wind music all their own. They flutter gracefully in even the lightest breeze.

The tree can grow in single or multitrunk forms; the white bark gets thick and scaly. Early pruning by an arborist helps the bo grow into a well-shaped tree.

One mission of botanical gardens is to record how and where plants and trees are grown as well as the plants we share. It's like backing up your computer files and shares the wealth. Foster Botanical Garden has shared bo trees with gardens, parks and churches with enough room to grow them to full potential.

In 1999, I asked Romel Silva, Foster Botanical Garden's great plant propagator, to make hefty air-layer cuttings of the bo tree. There were strong water sprouts that needed to come off and, we used air-layering propagation to grow them into specimen trees. We had in mind the Kahua Kuou section of Ho'omaluhia Botanic Garden, where the Indian and Sri Lankan plant collections are found. Romel made the air layers, and they're growing well.

A few days after Sept. 11, 2001, Darryl Barbadillo, the landscape director at the Hale Koa Hotel, asked if we had a bo tree that could be planted in memory of Christine Snyder, our arborist friend who had been aboard Flight 93.

We found a beautiful tree for the Hale Koa which Darryl and his staff planted in a corner of the hotel's Kuroda Field. This tree has space to grow regally, and it is doing just that in its peaceful yet vigorous way.

Visit one of these meaningful trees in our public spaces. Place your hand on the trunk and "touch trees," as we arborists say. We all live, breathe and enjoy life due to the oxygen and food that flourishing trees and plants produce.

Heidi Bornhorst is a sustainable landscape consultant. Submit questions at islandlife@honoluluadvertiser.com or Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802. Letters may be published or distributed in print, electronic or other forms.