Skip to main content

New roots for an old soul: extreme 30-foot plant cutting

A large contingent of students and staff was gathered when I arrived for my volunteer shift at the Conservatory Greenhouse at the University of Minnesota on the St. Paul campus. The crowd was on hand to help with the gentle felling of the largest plant in the greenhouse, decades old and 30+ feet tall.

Native to the island of New Caledonia in the South Pacific, this fern -- Sphaeropteris intermedia the largest of all tree ferns -- has been happily growing in the tropical room of the greenhouse for a number of years, to the point its fronds are brushing up against the glass ceiling panes of the roof. 

Tree fern fronds brushing against the roof of the U of M greenhouse

Rather than cut the tree down and lose the specimen, the staff decided to try to save the tree. The process would involve cutting off the top half of the tree and reinserting it into a new space in the soil of the greenhouse floor.

Months of planning and preparation

A well-known technique was used, referred to as air-layering, where a collar of moss was attached around the trunk at the midsection. The moss would be attached only after first wounding the bark to encourage new roots to grow into the moss (weeks to months). Then the next steps may occur in rapid succession: 
  • the canopy of fronds would be significantly reduced in number to match the capacity of the new roots to deliver water and nutrients;
  • the trunk would be completely sawed through once the new roots had been established in the root ball;
  • the top half of the tree, with its new root ball, would be carried to a new spot in the soil of the tropical room floor.

Moss collar into which new roots grow (air-layering)

The canopy is reduced to match the root ball capacity

Sawing through the tree trunk just below the new root ball

The tree was felled gently onto our shoulders, me in the middle on the right (photo courtesy of Adam Wegren)

The new root ball is firmly planted in the new location

The old tree stump will be sawed down and reused as a support for orchids

Making final adjustments to the new, shorter, tree fern

University of Minnesota Conservatory

The greenhouse on the St. Paul campus of the U of M is free and open to the public. The greenhouse is divided into two sections. The public section may be viewed free of charge during regular business hours during the week. To view the non-public collection, arrangements may be made with the staff for a private tour, also free of charge (donations are accepted).

Food of the dinosaurs

Tree ferns have existed on Earth since the age of the dinosaurs, more than 200 million years during the Jurassic period. With respect to other types of plants ferns predate flowering plants and conifers. Only mosses are older than ferns. Currently, there are 25 genera of tree ferns, with hundreds of species. Their range limited to subtropical rain forests of the Americas, Pacific Islands, New Zealand, and Australia.

My personal experience with tree ferns

A few times over the years I've had the privilege of hiking past tree ferns. Given their size and exotic appearance, I couldn't help but stop and stare at them. In one respect, the fronds look like any other that ferns spread across the forest floor, but the tree ferns tower overhead, rising on serious trunks. And, their eye-catching golden fiddleheads can be massive, larger than my own head. On the big island of Hawaii, there is an actual tree fern forest in Volcanoes National Park. And, I have vivid memories of hiking through fern-canopied trails of New Zealand, suffused with gentle green light. Magic.

Tree fern canopy, New Zealand

Dappled green shadows underfoot on the trail, New Zealand

Mesmerizing tree fern pattern on the forest floor

Hiking through a tree fern forest, New Zealand (photo courtesy of Tom Wilson)

Unfurling golden fiddleheads, Hawaii Volcanoes National Park











Comments

Popular posts from this blog

I celebrate learning this about cycad plants

I didn't know that the cardboard palm - Zamia furfuracea - is a cycad. It isn't a palm tree (don't judge me, I'm not a botanist). But it also doesn't look like the other more familiar types of cycads with their fluted upright palm-like fronds. I didn't know it is said to be the second most commonly cultivated cycad, after Cycas revoluta . I didn't know this plant is unrelated to the common ZZ plant - Zamioculcas zamifolia - although they have a similar appearance. Before today I didn't know any of these things, but now I am happy to have learned them. From the parking lot I walked to the U of M Conservatory greenhouse in near-zero F weather. Stepping into the tropical spaces was a joy of its own. But being able to learn new information and experience new procedures was a compounding factor. Joy squared. During my 3-hour volunteer shift, my initial task was to clean the parasite critters (mealybugs and scale) from the stems and leaves of the cycad, Zami...

The eponymous palm of Palm Springs

Tens of thousands of native California fan palms ( Washingtonia filifera)  rise over the gardens and streets of Palm Springs. The fan-like leaves flutter and wave as the trees gently sway in the desert breeze. If a plant could be described as elegant, this plant would certainly be one. Delicate fibers peel away from the leaf blade as they age, giving the palm part of its name, filifera . The advantage of the fibers to the plant is uncertain; however, the fibers were used by the indigenous Cuhuilla tribes for tools and fabrics. It is no accident the city is named for the palm. For centuries the native Cuhuilla residents were vastly outnumbered by fan palms. For the Cuhuilla, the plant became an important resource for their tools and shelters. Even today, I wouldn't be surprised if the number of palms outnumber the residents of the current modern city. Bird's eye view over old Palm Springs neighborhood; fan palms are everywhere. In their native environment, the palms grow best al...

Mobile indoor green wall

Finally, after three years... my plant vines have grown and spread to be green wall that I had hoped for. I'm not sure it would have taken as long if the plants were in a more humid, sunny climate, et cetera. But given our indoor Minnesota location - even with a southwest exposure - the vines have needed that amount of time to climb the six feet from the base to the top rungs of the metal grid supporting them. The result has been worth the effort. And to be honest, I didn't have to wait three years to begin enjoying the green wall. The vines were already attractive when only half way up the trellis. A metal grid is filled with mix of Epipremnum aureum cultivar "Marble Queen", Epipremnum aureum aka golden pothos, and Philodendron Brasil . Architecture of the green wall The initial intent of the project was to grow a green wall, in an apartment, that could be moved around to be able to clean underneath, and also to provide a mobile room divider for our open-plan loft....