HAWAI'I GARDENS
Uluhe fern deserves lots more respect

By Heidi Bornhorst

The uluhe fern grows profusely at the Ho'omaluhia Botanical Garden. Despised by some, it keeps invasive foreign weeds at bay. Eugene Tanner • The Honolulu Advertiser

Hike up into it and you might not like it so much, especially if you are wearing shorts. The plant with that light-green color is a native Hawaiian fern called uluhe. Some people call it false staghorn fern. It seems very vigorous and can be impenetrable. It can grow very tall as the somewhat viney fern clambers over itself. It can hide drop-offs, which is one thing some hikers don't like (better to stay on the trail!). If the fronds are cut or broken, the edges scratch bare legs.

As wild and vigorous as it can be, this fern is vulnerable, and it is not easy to grow in cultivation. A few years ago it was attacked on O'ahu by huge populations of the two-spotted leaf hopper and was harmed by the toxic saliva of the pest. Huge hillsides went from lush green to dead black. Weeds could come up through the soil that uluhe had formerly protected.

Before all kinds of aggressive weeds came to Hawai'i, uluhe was the plant that would often grow on a landslide or other damaged area in the forest. Other native plants then had a moist, well-composted (from old uluhe fronds) site to grow in. Today, the ferns often cannot grow in quick enough to stop all of the weeds.

During a conference earlier this year, we visited a garden in Anahola, Kaua'i, where the Hawaiian plants were all being nurtured and planted. Some people call this "restoration gardening." The garden had a wealth of uluhe. I was admiring it and telling the woman how lucky she was to have it and not to rid her land of it. The fern was beautiful and a good shrub height, about three to four feet. She could plant other good plants into the uluhe and not have to worry about weeds. She had planted hapu'u, ohi'a lehua, koki'o ke'o ke'o (the native white and pink, fragrant native hibiscus) and other choice plants into the bed of uluhe.

One of the men at the conference was from Maui. He said how he hated uluhe. I said, "You don't know how good it is till its gone and all the weeds come in." I tried to convince him of the virtues of the native fern.

This has made me really look at uluhe again. It is making a recovery on O'ahu in many places, and this is a happy occurrence. There are so many rapidly spreading and fast-growing weeds that can so quickly overtake Hawaiian forests. We need to cherish and protect and enhance what we have. We need to learn how to grow precious and gorgeous uluhe, as well as other Hawaiian ferns, to help restore our forests and improve watersheds.

Some good places to see uluhe are along the Pali Highway, where it is particularly lush because the crews don't chop it (they really should only whack the weeds and leave the native plants and ferns alone); at Ho'omaluhia Botanical Garden and along many of the moist hiking trails. Enjoy that refreshing, land-healing green!

Heidi Bornhorst is director of Honolulu's botanical gardens. Reach her by e-mail at islandlife@honoluluadvertiser.com.