Cultivation can help survival of native Hawaii gardenia

Who doesn’t love gardenias? Most Hawaii people, and gardeners in general, swoon for their fragrance and floral perfection. It feels like summer to us when kiele, or gardenia, is in bloom. We cherish the flowers and like to grow them in our gardens.

Did you know that there are over 200 species of gardenias in the world? They can hybridize with each other, and we then get new varieties.

We have three native Hawaiian species, and all of them are rare if not critically endangered here.

Gardeners and horticultural science have helped save our native gardenia in some ways, but there is so much more to be aware of and to do for these wonderful and unique plants.

Nau, or gardenia brighamii, has only 16 trees left in the wild. One is here on Oahu and the rest are on Lanai. There were some persisting on Molokai, too, not all that long ago.

Nau look something like a tiare or Tahitian gardenia in that they are single-petaled. They tend to have five to seven petals per flower. The fragrance, though, is completely unique. One of my Hawaii-plant friends (a man) described it to me as a “sweet coconut-oiled Hawaiian wahine on the beach perfume.”

I like to pick the buds of the one growing in my garden, hydrate them in a vase of water and wear them, or share them, for a really special occasion. Sometimes I even have enough for a lei! They seem to flower profusely after a good soaking rain, or sometimes after a nice full moon. Lately it’s been so dry, mine have not been flowering.

They were once fairly common in dryland Hawaiian forests, enough that Hiiaka made lei of them woven with pili grass when she was sent to bring Lohiau from Kauai to Hawaii island, or so the moolelo goes.

Nau is not easy to grow from cuttings, but if you can get viable seeds, those are fairly easy to grow. We now have many in home gardens and in our botanic gardens. Botanic gardens also keep track of where each plant is from. This is important.

Perpetuating them in the wild is vital. When Hawaii plant people hear about wildfires we cringe. We want to go out and help the firefighters and put out those fires, make firebreaks and restore the native plants back to the areas.

When the news says “no structures burned,” we are not totally happy, though we are glad folks and their homes are safe. Native plants and forests can’t run away from the fires. They are less of a priority to save than buildings.

But a building can be replaced. Native plants and their habitats cannot. Once they burn, they burn more because alien weeds, especially grasses, will quickly grow and spread in the burned areas. Every time it burns again, more of the weeds and pesky fire-loving plants grow rapidly, are prone to burn again, and in the end there are fewer native plants and forests.

The recent Nanakuli fire, so early in the year, was scary and huge — more than 2,500 acres — and it almost burned up the last nau on Oahu.

We need to make firebreaks there and make it a priority to put out fires in native forests. Replanting native forests will also help keep things cool and reduce fires.

Some seeds from half-singed gardenia fruits, with their viable golden seeds inside, were taken to Lyon Arboretum by Susan Ching- Harbin of the Plant Extinction Prevention program. Lyon will save some seeds and grow them to be planted back into the wild.

This is one of the ways that botanic gardens are a living repository of rare plants. Gardeners can also help.

Grow the native gardenia in your own garden. Support botanic gardens or volunteer to take care of native Hawaiian plant habitats in the wild. We can all learn more and na lima kokua, work together, to help perpetuate rare plants and forests in Hawaii. E ola nau.

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