Welcome to Friday Fiction Facts: sciency things that fiction writers need to know.

So was I once myself a swinger of birches;  And so I dream of going back to be. – Robert Frost

Stand of Birches in Northern Ontario ((CC) Douglas Stebila)

Pity the tree, a novelist’s throwaway reference, relegated to the margins of an otherwise colorful scene, referred to merely as, “the tree.”  If not that, then described with an over-used cliché – “stately elm,” “mighty oak,” “whispering pines” …

Of course, unless you are a Lorax, the tree is not your main character, so who cares? But in the way that writers are urged to add specifics to their descriptions (name brands, breeds of dogs) a properly defined and well-described tree can add richness and a measure of reality to a setting.


So this week:  Five things fiction writers need to know about trees —

1. Kinds of Trees

The word “spruce” entered the English language from Old French Pruce, the name of Prussia. Spruce was a generic term for commodities brought to England by Hanseatic merchants and the tree was believed to have come from Prussia. (Wikipedia: Spruce)

There are 100,000 species of trees. This means it should be easy to go beyond oak, maple, or pine for your story. Each one of these has different characteristics, regions where it thrives, and place it grows best.

For instance, birches grow in stands of same-aged trees that have taken over open areas. They are one of the first trees to colonize areas that have been scorched by fire or heavily logged.  Cottonwood trees grow along streams and rivers in order to survive prairie fires. The tree gets its name from the fluffy white seeds that blow all over. These settle in the water and some wash ashore and take hold as new trees.

In addition, some trees can add interesting color, links to history and mythology and metaphor to a story –none of which a writer will ever get from the word “tree”  —

Did you know that when Achilles kills Eetion during the Trojan War, the Mountain Nymphs planted elms on his tomb?

And in 1971, Apollo XIV astronaut Stuart “Smoky” Roosa, a former smoke jumper for the US Forest Service, carried the seeds of several species of tree, including the American Sycamore, to the moon to honor the USFS. Today the trees planted from those seeds, known as the Moon Trees, thrive in cities across the US.

Several species of truffles have symbiotic relationships with oak trees.

The Biscarrosse Elm 1350-2010

2. Lifespan

Trees have a specific lifespan.  If your story has soldiers camping in a 100 year old stand of birches, you would be mistaken. Birches only live 30-40 years.

On the other hand, The Biscarrosse Elm, a field elm (Ulmus minor), reputedly planted in 1350, died of Dutch Elm disease in 2010.

Legend has it that girls deemed promiscuous were forced to stand naked upon a barrel beneath the tree for a day. One unfortunate, unjustly accused, died of shame, the tree annually producing a corona of blanched leaves in her memory. (Wikipedia)

Once you know what kind of tree you are writing about, you can look up how long it might live. Here are some handy charts:

  • Lifespan of common Canadian trees in urban settings.
  • Lifespan of Virginia Trees
  • List of Oldest Trees

3. Size as a function of age

How old is this tree? (Virginia Tech)

Each species of tree is genetically determined to grow to a specific size at a predictable growth rate. Therefore, a writer can’t just toss out sentences like, “The 50 year old maple was so huge, that the three children couldn’t get their arms around it.”  That may not be true for maples.

A shagbark hickory with a 10 inch diameter and competing with other forest-grown trees can easily be 75 years old while a neighboring red oak with the same diameter would only be approximately 40 years old. (About.com)


So how do you figure out a tree’s age as it relates to size?  

There is a formula for that!  :  Diameter (inches) x growth factor = tree age (years)

1. Determine the kind of tree
2. Determine tree diameter in inches measured at 54 inches (chest high) above ground. (Diameter = circumference divided by 3.14)
3. Find the Growth Factor for your species of tree using the table here for common North American trees.
4. Do the math

(Then cross check that with average lifespans for that species.)

For the fiction writer, this formula probably works better in reverse. Imagine a story where the grandfather planted a red oak tree 50 years ago. How big around would the trunk be today?

Age / Growth factor = diameter (inches)  –>   Diameter x 3.14 = circumference
50 years / 4.0  = 12.5 inches diameter   = 39.25” around

‘Honeycrisp’ TM apple tree

4.  Apple Trees

Apple trees do not work the way many people think.

Yes, you can plant an apple seed and, after some years, you will end up with an apple tree and fruit. But here’s the thing:  Due to a trick of genetics you will not end up with the same kind of apple you planted. In fact, you will end up with a never-before grown kind of apple that may or may not taste very good.

When you see an endless orchard of Golden Delicious apples, these were not grown from Golden Delicious seeds.  Every tree in that orchard came from a shoot (or “scion”) from an existing Golden Delicious tree that was grafted onto rootstock.

Today, if you buy an apple tree, it consists of both parts – the scion, which determines the type of fruit you get, and the rootstock which determines the maximum size of the tree (and thus, years to fruit production). The rootstock may also provide some resistance to specific pests or environmental stressors.

The choice of root stock allows orchard owners to select the stock that best suits their environment while still producing the type of apple they want.

Then where do new kinds of apple come from?

Since every apple seed planted creates a new kind of apple, experimental cultivators plant many seeds hoping that one will result in the next consumer favorite. University of Minnesota’s Horticulture Experiment Station, cultivator of the immensely popular Honeycrisp (TM)* apple, is one such place.

*Names of new apples are trademarked by their cultivators. 

Oaks with Canker

5. Some really great tree words you might enjoy using —

Xylem and Phloem (the little tubes that get water & nutrients to all parts of a tree)

Conifer (trees with cones)

Catkin (those fuzzy caterpillar-like flowers on trees; from the Dutch word for kitten)

Punk or punky wood (fallen wood that has started rotting but hasn’t turned soft; great for fire-starting)

Pippin (one of several words used to describe an apple that came from a tree grown from a seed)

Samara (the little “helicopter” things that fall from Maples and other trees; actually a fruit!)

Canker and Anthracnose (general terms for tree diseases that result in “sores” or those bulgy lumps and bumps on trees that inevitably morph into faces when you’re lost in the woods.)

Widowmaker (term used by loggers to describe a high branch that is broken or dangling and may fall and kill someone at any moment)

Gall (outgrowths on trees, sometimes caused by insects, disease, or fungi; some galls are used to make ink or ointments.)

And now, in case your main character is lost in the woods and needs to make a fire, here is how to start a fire with punk wood