Giants Among Us

As a child growing up near the Susquehanna River in northeast Maryland, I was surrounded by many tulip-trees in our woods. Some I just dreamed of climbing, but the first branches were usually more than 40 feet from the ground. There was a smaller one in our back yard where I managed to get to the first branch (and only the first branch). Every day when I took my dog for a walk, we would go by that tree and I would look up and think, “Man, if I could only get to the top—imagine the view from up there.” I never did get to the top of that tree, but here at Longwood I have climbed many trees that are higher than the 70-foot tulip-tree in my backyard.

Arborist pollarding in the Italian Water Garden

Longwood Gardens has so much to offer in the way of trees. Thanks to Pierre du Pont, we have this beautiful garden and its amazing old trees. Pierre bought the land for exactly that reason: to save a group of trees. The trees that he saved are incredible specimens, but I am here to tell you about the giants living among us.

Pierces Park 2006.

Among our giants, one stands out. The tree, a tulip-tree (Liriodendron tulipifera) we’ve named Pierre’s Poplar, is located on the Forest Walk in the northern part of the woods.

Location of Pierre’s Poplar.

It has been growing there for many years, hidden in a valley right off the trail that bisects the middle of the woods. Thanks to Scott Wade, State Coordinator of the Champion Tree Program who discovered the tree, Pierre’s Poplar has been put on the map. It is now on the Pennsylvania big trees list and is a major player among the trees at Longwood Gardens. The giant measures in at a whopping 164.2 feet tall, with a circumference of 146 inches and a spread of 73 feet. It has a score of 329 points on the registry. The tree is the tallest recorded Liriodendron in the northeast United States.

Liriodendron tulipifera (leer-ee-oh-DEN-drawn too-lih-PIFF-er-uh) is a scientific tree name that just flows off the tongue, doesn’t it? Most people refer to the tree as a tulip-tree or tulip poplar, but the Latin sounds better to me. Many know what a tulip poplar is and how to spot them in the forest because of their long straight trunks and wide-spreading canopies. It is one of America’s tallest native deciduous trees and can grow up to 200 feet tall.

Tulip-trees in Longwood’s Forest Walk.

In this short video, the arborists are climbing and measuring Pierre’s Poplar.

To climb a tree this tall, I first use a big shot (like a giant sling shot) to set the access line on a branch high in the tree. I ascend to the end of the access line. Next I advance my rope by throwing the line to the next highest branch and continuing to climb.

We measure the height of the tree by raising a pole to the tip of the highest branch. The pole has a line attached that extends all of the way to the ground. The arborists on the ground mark the point where the line touches the ground and the tree’s final height is determined by measuring the length of the rope.

We measured the height of the tree to be 163 feet—that is half the length of a football field!

The tallest recorded tulip-tree, with a height of 191.9 feet, is named the Tall One and is located in the Smoky Mountains of North Carolina. A member of the Eastern Native Tree Society just discovered the tree last year. It took a team of five arborists to climb and measure it. They had to hike in four miles to the remote undisclosed location of the tree. The Eastern Native Tree Society is a great group of people who are finding and documenting huge trees. Thanks to that group for the work they do to preserve our forests.

The tulip-tree, or tulip poplar, is often thought to be in the Poplar family, but it is not. It is of the Magnoliaceae family. The wood from tulip-trees is used for furniture and cabinet making. The wood has a deep purple/bluish stain that some people find attractive. It is easy to work with and is fine-grained. Even though it is great for furniture making, the wood can be weak and brittle in the tree. It has a tendency to be broken up in storms, as is the case with any improperly pruned tree.

Tulip poplar chest made locally for Pierce family circa 1840-1900.

There are giants among us—in our local forests, parks and gardens… you never know what may be found. Measuring trees, or simply learning to appreciate and enjoy the trees and forests in the Brandywine Valley, especially at Longwood Gardens, is a challenge that awaits everyone willing to put in the time and effort.

I hope that you can join us as we celebrate Arbor Day this Friday and Saturday (April 27 & 28, 2012). We’ll be on hand to answer your tree-care questions, kids will get the chance to gear-up and experience what it’s like to be an arborist, you can tour our Champion Trees, and more.

Tulip-tree in the Lookout Loft treehouse.

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Grow in Green: Biodegradable Pots

Biocontainers offer an exciting opportunity for plant producers and home gardeners to become more earth friendly. Currently the majority of ornamental crops are produced in petroleum-based plastic containers. The extensive use of plastic results in a significant waste disposal problem and the plastic ends up in a landfill or hopefully gets recycled.

Biocontainers are containers that are not petroleum based and will degrade rapidly when placed in a composting operation or when field planted. Biocontainers fall into two categories: compostable biocontainers, which are designed to be removed from the rootball before the final planting and composted; and plantable biocontainers that are designed to be left intact on the rootball and planted directly into the field, landscape bed or final container. These biocontainers are designed to allow roots to grow through the container walls and to decompose after being planted. Some of the concerns when using biocontainers are the physical strength of the container and biodegradability.

Despite the introduction of many types of biocontainers, limited research has been conducted to evaluate these containers. Therefore, studies to test container wall strength and biodegradability was undertaken at Longwood Gardens, Louisiana State University and University of Arkansas.

Name and composition of biocontainers tested
Container Name	Container Composition
Plantable
Peat	Peat and paper
DOT® / Fertil®	80% Cedar wood fiber, 20% peat and lime
Cowpots®	Composted dairy manure and a binder
Cocofiber	Coconut husk fibers and a binder
Strawpots®	80% Rice straw, 20% coconut fiber and a binder
Compostable
OP47	Bioplastics
Paper / Kord Fiber	Paper pulp and a binder
Ricehull	Ground rice hulls and a binder

Container Wall Strength
To determine container strength, containers were filled with potting substrate, placed in a greenhouse and watered once per day. After four weeks, substrate was removed and the force required to punch a 0.2 inch probe through the side of the container was measured. This was done to simulate the force it would take a finger to puncture the container wall.

Plastic had the highest strength followed by paper containers. Cocofiber and ricehull containers were stronger than the remaining containers and of all containers tested, peat, Fertil and Cowpot containers had the lowest wall strengths.

This test is important to determine whether a container possesses enough durability when being handled. The researchers found that if a container’s wet wall strength was less than 2 kg, the containers tended to tear or break and handling became difficult. In this study, all containers had adequate wall strengths except Fertil, peat and Cowpot containers, and thus handling of these containers when wet was difficult and could make them problematic for some growers.

Decomposition of Plantable Biocontainers
Vinca ‘Cooler Blush’ were greenhouse grown for 6 weeks in plantable biocontainers and transplanted into outdoor beds with the biocontainers were left intact on the rootball. After 8 weeks, the level of decomposition of the container was determined and expressed as a percentage of the original dry weight of an unused container.

Cowpot containers had the highest level of decomposition, cocofiber had the lowest and all other containers were intermediate. Variation in decomposition rates are likely due to the differences in container composition. Those made of high cellulose materials, which decompose easily, such as Cowpots, had higher rates of decomposition than those with high amounts recalcitrant materials such as cocofiber. Additionally, nitrogen in the dairy manure used to produce the Cowpot containers may have stimulated the activity of microorganisms and subsequent decomposition rates.

Container strength and biodegradation varied among the different types of biocontainers tested. Fertil, peat and Cowpot containers had wet strengths low enough to make handling difficult. On the other hand, these biocontainers were the fastest to decompose in the landscape. Depending upon the crop, cultural conditions and handling, different biocontainer properties will be more or less important. Plant producers wanting to improve sustainability by switching to biocontainers will need to evaluate which of the properties are the most significant and choose a biocontainer that best fit their needs. For more information on biocontainer physical properties please see Evans, Taylor and Kuehny. 2010. Physical Properties of Biocontainers for Greenhouse Crop Production. HortTechnology. 20: 549-555.

This project was funded by the Arkansas Division of Agriculture, Longwood Gardens and The LSU AgsCenter.

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Stick Dinosaurs, Big Bugs and Pollinators

Longwood welcomes David Rogers to “Behind-the-Plants!” David is an artist specializing in larger-than-life sculptures made from natural materials. Several pieces from his Pollinators series are on display now in Longwood’s Idea Garden, through September 6.

Bee and Flower

My very first commission at a public garden was at Longwood in 1993. It was a dry branch construction called the “Stickasaurus.” This sculpture was my interpretation of a ‘stick’ dinosaur’.

At the time, no other artist had worked on site doing a full-scale work in progress. It created quite a stir and many visitors showed up weekly, if not daily, to watch the work progress. It was both challenging and extremely exhilarating at the same time. I created that piece in the fall out of materials all found on the property. The finished piece measured some 40′ long x 12′ wide x 15′ high.

After the piece was completed and showed during the Chrysanthemum Festival it was partially dismantled and stored. A year later the segments were relocated and rebuilt on a private client’s property in Pound Ridge, NY where the Stickasaurus still stalks its prey.

Subsequent to that installation I exhibited three more projects here at the Gardens. In 1995, my traveling exhibit called “Big Bugs” featuring much-larger-than-life sculptures of arthropods all made from natural materials came to Longwood. This exhibit has been very successful and has been touring botanical institutions in the US for the last 15 years.

As the Big Bugs grew, expanded, and matured, so did I. The challenge of having a very successful nationally touring exhibit made for a very interesting learning curve. The demand for the show coupled with the collective mission statements of the host institutions made for a demand for more pieces with educational tie-ins. So I went to work on some very specific kinds of animals. In some promotional materials that I used with the Big Bugs exhibit,  I had written about a new group of pieces I’d hope to create. These pieces would be called the “Pollinators Series.”

In 1998-1999 I debuted some of these at the “Art in the Garden” festival at Disney World. These pieces included the Bee and Flower (see above), Bee and Hive and Butterfly. I never got around to the Hummingbird, as was my intention.

Hummingbird

Last spring a call came from my friends at Longwood and they wanted the Pollinators, but the hummingbird was an absolute must if we were to have a successful exhibit.  I agreed. So now I had to create my first bird. It was a different kind of challenge for me, after all, I’d spent the last 16 years working on animals that had 6 or more legs!

I chose some new woods I’d never worked with before to create the Hummingbird. I selected Tulip Poplar for the bird’s body and wings and Ambrosia Maple for the flower petals. “Ambrosia wood” is any wood that has been infected with the ambrosia beetle. The interaction with this insect creates quite a bit of staining within the natural grain of any wood it attacks.

Now that the new exhibit is here and installation is complete, I have the great joy of seeing my art work once again in a truly amazing garden. It all fits together very nicely in the perfect natural environment.

As an artist, one thing I really work on is trying to find the symmetry. Coming back to Longwood to debut The Flower Force: David Rogers’ Pollinator Series featuring the new Hummingbird and Flower has a lot of meaning and symmetry for me.

Butterfly

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