Foster Botanical Garden of Honolulu

 Urban tropical garden

One of the joys of travel is the ability to visit special places where people have poured their hearts and life’s work. This year we took the opportunity visit a couple of Honolulu’s famous botanical gardens, the product of many visionary people over the span of more than a century.

Foster Botanical Garden is arguably the jewel in the crown of five botanic gardens scattered across the island of Oahu, and all of them belonging to the Honolulu Botanical Gardens. Now occupying a combined  650 acres, this organization is a division of the County of Oahu which maintains the gardens.

Foster Botanical Garden is situated in the heart of Honolulu, not far from the old Iolani Palace. Over the past 150 years of its existence it has grown in size from 4 to 14 precious acres. In 1850 Queen Kalama ceded the original land to Dr. William Hildebrand who was one of the physicians of the royal family. He was also a noted botanist, author, and plant collector. When he returned home to his native Germany, the land was then sold to a wealthy merchant family, the Fosters, who held the property until the 1930’s when the garden was donated to the city. While the hotels and skyscrapers gobbled up the town, the Garden has remained an oasis in the middle of it all.

It is said the garden was the inspiration for the line in Joni Mitchell 1970 folk song “Big Yellow Taxi”: “They took all the trees, put ‘em in a tree museum/ And they charged the people a dollar and a half to see ‘em”. …../They paved paradise and put up a parking lot.”

Queen Kalama, 1862 (public domain photo)

The tree collection

I can’t possibly write about all of the hundreds of fascinating trees in the collection - and you’d be bored beyond tears reading about all of them. But I can briefly mention a few examples originating from different continents. In a later post, I’ll write about a few native Hawaiian trees form another of the five gardens.

Central American quipo tree

This ginormous tree is in the hibiscus family Malvaceae. The official Latin name is Cavanillesia platanifola. According to Wikipedia it is a lowland tree of the Central American countries and northern South America. The trees grow to 200 feet tall, and amazingly the leaves at the top of the tree are present for only one month of the year…I suspect to conserve water from evaporation in the heat…the tree has to maintain its vast size with so little resource from its short-lived leaves! It is said the tree holds so much water a root fragment can be tipped to pour watery sap that tastes of potato. The wood is very soft, like balsa wood. The Foster Garden’s tree was planted in the 1930s.

That’s me! At the bottom, touching the smooth bark.

At > 100 feet tall, it looks like a water tank and in some ways it is!

African baobab tree

What tree could be more poetic than the baobab? It dominates the African savannah in so many stories and movies. The official Latin name is Adansonia digitata, it is also in the hibiscus family of Malvaceae. As one would expect for a tree growing on the dry savanah, it has a fleshy trunk which can store a lot of water. 

The Foster Garden’s baobab is appropriately gigantic too, ‘though I think it would be considered a young shrimp compared to some of the trees in Africa which can be up to 2000 years old. This example is a comparative infant, planted  sometime in the 1940s.

African baobab

Cycad trees

Before there were flowering plants of any kind, before there were conifer trees, even before any dinosaurs roamed the land, there were cycad plants. They look like palm trees, but they are much, much older in terms of evolution. At one time they dominated all plant life on Earth - along with ferns which is another story. So, what happened to all the cycads? It turns out that evolution happened to them -  the conifer trees and then the flowering plants eventually have out-competed the cycads and crowded them out of every continent, almost to extinction after hundreds of millions of years. But still even today some varieties of cycads are native to just about every continent except Antarctica - where they also once thrived BTW.

From personal experience of handling them at the greenhouse conservatory of the University of Minnesota I can vouch that cycads are very tough plants indeed! They have hard plastic-like leaves with razor sharp edges, and the bark is covered in equally dangerous scales. Having repotted and cleaned the parasites off of cycads from 6 inches to 6 feet in height they can easily shred the skin off my arms. I have learned to carry bandaids and alcohol wipes in my gear. How it is that dinosaurs dined on cycads is beyond my imagination.

Most cycads reproduce with male plants sporting male cones and female plants with female cones. Cycads depend on insects, typically beetles, to pick up pollen from the male cones and wander over and deposit the pollen in the female cones. As depicted in the photo, the cones can become huge in order to attract sufficient attention from insects. This plant, Encephalartos gratis from Africa has a cone at least 3 feet in length.

The main difference between cycads and palms is that cycad produce seeds in cones, whereas palms trees are flowering plants that produce seeds within fruits. Palm trees evolved much more recently, about the time of the great dinosaur extinction 66 million years ago.

Cycad cone, 3 feet in length

Encephalartos gratus, a cycad from Mozambique

Cycads depend on insect pollinators, beetles and bees.

Botanical gardens are our past and our future

The Honolulu Botanical Gardens are a gem, and I’m so grateful for the people who recognized the importance of preserving enough of our environment to be able to teach it to future generations. The tenacious 14-acre foothold of Foster Garden in the middle of a crowded city is a modest but important fragment that was a pleasure for me to see.