At its very heart, Reeves Reed Arboretum is a museum of trees. It’s a place where people come to discover trees, really see trees, celebrate trees, learn about trees, embrace and honor all that we love about trees, and nature in general. One of our most stately and iconic trees here at the Arboretum is our great, old Sugar Maple Acer saccharum that majestically shades the Daffodil Bowl. Estimates of the age of our Arboreal Leviathan vary, but my guess is between 100 and 150 years old. Our iconic Maple has witnessed much history in its lifetime and survived its share of storms, droughts, plagues and human interference (yes, it’s sadly true).
I like to think about all the wonderful human interactions that have taken place under our famous tree, such as countless family photos, parties, engagements, first steps, joyful first meetings and reunions, happy conversations, sad conversations, parting thoughts, goodbyes. Trees bear witness but they never share our secrets. Over its long lifetime, thousands of people have walked under its graceful boughs, some aware of its majesty, others, maybe not acutely but passively. Undoubtedly, our tree has been there for people, a silent witness to the interactions and interconnectedness of every human that’s ever gazed upon it or walked below its sinewy branches. One must also think about all of the non-human interactions our tree has welcomed and endured. Just think of the countless songbirds, insects, squirrels, birds of prey, chipmunks, racoons, owls, even snakes and lizards that have lived, worked, raised young and rested upon its welcoming arms…. As a hopeless tree lover, to me…our maple is our very own sylvan hero.
About 8 years ago or so, our Maple started showing its first signs of decline; weaker annual growth, smaller, less numerous leaves and increased brittleness. Around that time a very large main branch was ripped from the trunk in a fierce storm, leaving a large gash where it was originally attached. Cables, put up years ago to protect the tree from falling apart and from lightning, did help to keep the tree from entirely shattering. But there was significant damage done. Ever hotter and in some years, drier summers increased the overall difficulties facing our tree. Noticing this, the Horticulture Department had the soil around the tree air-spayed, which helps to rectify soil compaction, and a large area around the tree was mulched to help the tree’s sensitive feeder roots conserve moisture and regrow. Undoubtedly, these actions have given us more time and allowed us to savor our tree for a few more years. The future however doesn’t look so good for our old Ent-Like friend. Sugar maples don’t often live much past the two-hundred-year mark in the best of circumstances, unlike White Oaks for example which can live 500 years. Our tree officially retired from being an active sap maker several years ago as the writing was on the wall (or trunk, so to say) and drawing sap would be just an extra drain on the health and resources of a declining tree. During our yearly March Sugar Maple Festivals, we teach our visitors about the art of maple sugaring, select younger healthy and vigorous maples for sap drawing and always point out our grand old Dame over the Daffodil Bowl, explaining its history and reason for retirement.
When I started four years ago as the Horticulture Director, I immediately was drawn to the Sugar Maple. I was simply awestruck my first Spring when I saw the tree in flower, looking like a giant cloud painted Key Lime pie green, catching the sunlight in an indescribably beautiful way as the Daffodils below were singing its praise in matching yellow. I noted later that season though that the leaves were small, stunted and discolored, and the tree was growing very, very little. There was also evidence of much dieback amongst the highest branches. It was clear that this beautiful tree was declining, and we needed a plan.
Our tree has obviously reached an impressive size and stature-pictures of the tree in its prime show what a near-perfect specimen this individual Maple was. Not all trees, however, are created equally. There is much genetic variability within the genome of sugar maple. Some grow more upright, some spread more, some have denser foliage and branching while others can be quite sparse in their twiggy frameworks. Most are beautiful in autumn when the leaves turn into shades of yellow, orange and in some cases crimson, however some may have disappointing brownish yellow foliage come October and November. Not our Sugar Maple though! Our tree was an autumn showoff, as can be seen in many photos taken of it over the years, and the branching habit of our tree, before its wind induced damage, was truly exceptional. Although we harvested many seedlings of this tree, genetic variability in seedling material means that daughter trees could vary tremendously in habit and form and autumn color. Although having seedlings around and planting them in areas throughout the Arboretum is always a great plan for genetic diversity, to have a replacement tree that would someday look just like our original can only be accomplished one way, and that is by cloning.
Plants can be propagated in two ways, sexually and asexually. A sugar maple that has its receptive blossoms pollinated by wind carrying appropriate pollen from another sugar maple will produce fruits called samaras immediately after flowering. They will slowly enlarge over the summer until autumn, when they will mature, turn brown and fall off. The ingenious natural design of the samara allows it to helicopter down from the parent tree, usually landing far enough away to germinate out of the shade of its mother tree. As trees produce millions of seeds in years of bloom (most sugar maples bloom every other year, producing only larger and fuller leaves in off season), there are many that will not grow. Nature is always sure to produce enough surviving seedlings and later saplings that will have a good chance of growing. Sugar maples are extremely tolerant of shade so even if many do sprout in the shade of their mother tree, they will be able to grow in filtered light for many years, awaiting an eventual hole in the canopy that they can take advantage of and grow more quickly and vigorously into the light. In another extremely clever act of nature sugar maple seeds will wait for a period of close to six months until germination. Factors such as several months of cold followed by moisture and warmth activate the seeds. The embryos enclosed within the rotting samaras expand and pop out of their protective coating, ready to unfurl their leaves and grow with the help of springtime’s increased sunshine and rising temperatures.
Asexual propagation in sugar maples needs the assistance of a person to work. In order to successfully clone a sugar maple, it must be grafted. Grafting is when you take parts of two distinct trees and join them together, for the purpose of propagation. Grafting is actually quite simple. For our Maple, cuttings were taken from twigs that are less than one year of age, which had been growing vigorously the previous summer. The cuttings, called scions, are 3-5 inches long and cut at a slant. Then sugar maple seedlings – these can be from any source as long as they are hardy, are then prepared for grafting. The seedlings should be about the same size or just slightly larger than the scion wood, and about 3 years old. They are cut at an angle as well (an opposing angle to the scion) then the stems (one loose, the other growing in a pot) are tied or waxed so they stay together and combined into one stem until the cells naturally fuse together. In human terms, this is kind of like a wound to the skin which is temporarily stitched together and will eventually heal and fuse together. Several months later when the two stems have hardened off and become one, any remaining growth from the understock is removed, and a new little tree has been created. The scion will grow and get larger and being that it is genetically identical to the mother tree from which it is cut, it will be a perfect genetic clone. As the graft grows any growth that originates from below the graft union will always need to be removed as it will not be from the cloned tree but from the understock. As the cloned tree grows it will have a habit very similar to its original plant. We are currently attempting to graft our Sugar Maple. I recently cut the scion wood from the tree using a pole saw, about 40 pieces of 6–8-inch twigs were sent via mail to the grafter and there are 15 understock plants waiting to be grafted within the next few days. After growing them on for a few years, they will be ready for planting. We will select one to plant in a spot directly next to the original tree, as a tribute to our great and beautiful Sugar Maple. When the sad day comes for the original to be removed, because of this grafting process, it will have a successor with the same genetics to take its place.
Our Maple is the first of what will be many legacy trees that will be asexually propagated to preserve their unique genetics. To do this, we must identify trees of merit, then determine the best way to propagate them. We hope to eventually be able to fund a propagation bench in our hoophouse so we can do this work in-house. Increased funding is needed to care for and protect our signature trees, especially as climate change complicates the growth and health of our trees. We hope to propagate many of our most historic and iconic trees in the same way, such as our Elephant tree and Ginkgo trees amongst many others. Stay tuned for more updates.
