Maple Mania

The maple trees in general are the genus Acer.  Maples are very common here in Indiana, you very well may not know all your local maple species. The Boxelder for instance is actually a maple. The scientific name for Boxelder is (Acer negundo).  The word Acer of course means it is a maple, and the word negundo makes reference to the pinnately compound leafs found on the Boxelder.  So if you are ever in a trivia game, and the question is, “Name a maple with a compound leaf”. The correct response would be Boxelder. At this point you are probably scratching your head, wondering. What exactly makes a maple, a maple?  That is quite elementary, they are the trees that have little helicopters on them.  Well, that is how I explain it to children. In the serious world those little helicopters are called Samaras, plants are actually classified based on their reproductive parts, even though most folks focus on leafs. All oaks have acorns and all maples have samaras.   Having said all this you should now understand why Boxelder is actually a maple even though the leafs look nothing like our other maples.


The most common tree in Indiana is actually the Sugar maple, there is an estimated 357 million Sugar maples in Indiana. The Scientific name for Sugar maple is (Acer saccharum). The word Acer meaning maple and the word Saccharum is Latin for sugar. Back when I was having to learn all these scientific names, I noticed how similar saccharum was to the word saccharin.  Most all of us know saccharin as a sugar substitute. Now I have given up my secret for remembering this one.

Trees have a variety of uses besides the obvious lumber and firewood. Trees also give us food and medicine, while providing shade and slowing storm water runoff. Our friend the Sugar maple is famously known for its use in manufacturing beautiful furniture and even musical instruments. Usually if I say Sugar maple the first thing that leaps to mind is maple syrup.  There is a local festival that can teach you much more about maple syrup production than me, but I will give a simplified explanation of the  process.

In early spring Sugar maple trees are tapped as the temperatures are warming and the sap is rising.  This sap is collected; the sap is only about 2 percent sugar so it is heated to evaporate excess water. This heating is usually done in a building called a sugar shack, sugar shed or sugar house, you notice the theme.  Popular lore said that a hunter’s wife once found this sap dripping from a sugar maple, which she then collected and used to boil a piece of meat. The meat was sweetened by the process.

The first actual written account of maple syrup’s use, was by a French explorer named Andre Thevet in 1557. Some of these early accounts liken the drinking of the sap to drinking a fine wine.  As with many things there is an Indian legend about the accidental discovery of maple syrup. In this account a chief stuck his tomahawk into a sugar maple tree and the sap ran out into a vessel and a little girl boiled the contents of the vessel, discovering the result was a pleasantly sweet liquid. Some accounts mention Indians letting swallow vessels of sap freeze then throwing away the ice. I can see how that might work. The European settlers preferred the heating process.  It really doesn’t matter how it was discovered, the take home information is that, the process has been around a very long time and Sugar maple sap needs to be concentrated to make our beloved maple syrup.

The question that comes to mind is does tapping a maple tree harm the tree.  From a purely biological stand point, yes the tree is injured.  Technically trees are not capable of healing, meaning they don’t come in and replace damaged cells like us, the process a tree uses is called compartmentalization, which means the injured area is sealed off from the rest of the tree. The tree will typically suffer no adverse effects overall, assuming if it is healthy and growing well at the time of injury. The syrup industry has evolved technics that minimize any harm to the tree. The important thing is to drill a small hole and not drill it very deep the syrup industry strictly regulates how many taps to install per tree.  The tree is the beginning of the process, so the syrup industry is keenly focused on preserving the tree while extracting sap from it.  Pruning maple trees during the early spring when night time temperatures are around freezing causes sap flow too.  I have been a practicing arborist my whole adult life, so I have had concerned customers ask me if this “bleeding” harms the tree.  In my experience it bothers the customer more than the tree.  I liken it to donating blood, giving some is not going to hurt anything.  Trees are multi-part systems that are naturally set up to lose a limb or 2 during its life.  The main harm that can come to a tree from a wound is the invasion of fungal organisms, the timing and small hole size of the syrup harvest helps to minimize this risk and making proper pruning cuts also minimizes the risk from pruning injuries. The main problem I have experienced over the years with pruning maples in the early spring is customer complaints, so it is best to avoid very early spring pruning of maples to help avoid that sticky sap mess that can be problematic.  The syrup industry has done a great job of developing techniques that minimize tree injury, this started in 1860 with the development of the first metal tap. They also get maximum efficiency of the sap that is gathered helping to minimize the amount of sap that needs to be extracted.  Remember syrup has been being extracted from sugar maple for hundreds of years and it is still the most common tree in Indiana.  In conclusion enjoy the Maple syrup festival and don’t worry about the maple trees.

Greg Mills
City of Salem Arborist