HAWAI'I GARDENS
Air layering lets you shorten tall plants
By Heidi Bornhorst
Q. Can you air-layer palms (monocots)?
A. Yes you can air-layer palms, which are monocots. This works well for Chamaedorea metallica and other species that have grown too tall and gangly for your taste. You make an air layer around existing, dormant aerial roots, and these will emerge into the moist sphagnum moss of the air layer and form a root ball to make a new, shorter palm.
A modified method of air-layer propagation on a monocot is to cover the keiki that appear on old red and pink ginger flowers and wrap moss around them while they are still attached to the mother plant. Pot up the well-rooted keiki in a few months.
Hiking sights
We went hiking Saturday on the Manoa Cliffs Trail, reached via Tantalus. It's a popular, well-maintained path, cared for by the state's Na Ala Hele program.
The trail was steep in places, but well-built with recycled lumber and gravel steps on the initial steep, muddy ascent. There are a lot of native plants to see.
The Na Ala Hele trail program relies heavily on community support for trail reconstruction and other special projects. If interested in giving your kokua, you can call Na Ala Hele at 286-9101.
Curt Cottrell, who is in charge of Na Ala Hele statewide, says this is one of the first and most durable volunteer trail projects, using recycled wood and gravel to make steps in place of steep mud. One section is built from Maui recycled lumber. Marines and many Boy Scouts hauled 70 tons of gravel to make the steps less slippery. This incarnation of the trail has held up well for eight years now.
The trail actually is more than 100 years old. It started as a charcoal cutters' trail, according to naturalist Lorrin Gill. A few years back, Na Ala Hele split the trail, calling the Pauoa segment Kalawahine to reflect its geography.
Introduced plants and weeds line the trail in the beginning. In the foreground of the trail, there are some natives: 'ohi'a lehua, lots of flowing 'ie'ie, small koa trees. Lehua 'ahihi, a Ko'olau endemic, alluded to in the mele "Aloha 'Oe" by Queen Lili'uokalani, is fairly abundant along the way.
Lama, one of my favorite native Hawaiian trees, was gorgeous with its black trunk, intricate branching patterns, small almond-shaped leaves, and bright golden orange and red fruit. It was lovely silhouetted against the greens and golds of the valley wall in the far distance.
On the way back, the trail always looks different. We spotted 'ie'ie in fruit, some of it already ripe orange and eaten off — by native birds, or by alien rats?
We saw vigorous 'ie'ie growing up on 'ohi'a lehua and koa trees, and a skinny, tendriled 'ie'ie growing up an alien Chinese banyan tree. Looking at the banyan, we could see how it got nicknamed strangler fig. We all hoped the 'ie'ie would win the battle.
There are many great trails on the Islands, and we can all help to maintain them and enhance the native plants and animals that still thrive here.
What's in bloom
Cercropia, an alien weed, is in bloom. Seeing wind-blown, curled-up, silver-underside cercropia leaves on my hike reminded me how great they are in Christmas wreaths. There were only a few mature trees along the trail, but they have the coolest flowers: In typical euphorbia-family fashion, they come in threes, with three long, silky light-brown panicles hung among the silvery, boldly indented curling leaves.
Lyon Arboretum, in the back of Manoa, is a good place to see this plant and many more.
Heidi Bornhorst is a sustainable landscape consultant. She has retired from Honolulu's botanical gardens and now volunteers there.
