44. Mature Tree Size
How large should I plan for my tree to get?
As an architect, I am used to drawing detailed, dimensioned plans down to the 1/8” of an inch of precision. How do you draw a tree that not only is irregular, but grows over time?
I asked a landscape architect friend, what age does she show her plants on a planting plan? She told me she draws the size of the tree at ten years.
I had to wonder, but what about mature size? What if a tree gets much larger later?
Why does the size matter?
Not planting trees too close to each other seems like an obvious rule, but what if it takes a lifetime before they reach their mature size? Who am I designing for? A theoretical person in the future, or me, the person who is living in my garden now?
Right now I am planning my street trees, and I keep going back and forth with what size I should show the trees. Anecdotally, all of the plants I have planted so far have stayed miniscule, so the promise of their advertised mature size is hard to believe.
As an architect, I want to control the end result of any design, so ideally I could come up with a graphic short hand for a tree that effectively describes what the tree will look like during my lifetime in the garden.
Case Study — Accolade Cherry Trees
Let’s zoom in on my Japanese Accolade Cherry trees that I planted last year; labeled JC in the image above.
This is what they looked like last spring — so insignificant, you can hardly make them out in the photos — and not much growth in the trees since then. I know the saying “first year sleep, second year creep, and third year leap” — I will believe it when I see it.
This is how the cherry trees actually look in plan as of today — highlighted orange to help you see them better:
Let’s review the plant specifications:
Japanese Cherry Trees (JC) — Accolade Cherry Blossom Tree
Mature Height: 20-30 Feet
Mature Width: 20-25 Feet
Sun: full sun
Flower: translucent seashell shaped
Flower Season: early spring
Question: at what age does a is a Japanese Cherry Tree reach mature size?
I asked my trusted helper, ChatGPT, and here is what it said:
Japanese Cherry Trees (JC) — Accolade Cherry Blossom Tree
Mature Height: 20-30 Feet
Mature Width: 20-25 Feet
10 year Height: 10-15 feet
10 year Width: 10-15 feet
3 year Height: 6-8 feet
3 year Width: 4-6 feet
Years to reach mature size: 10 - 20 years
Lifespan: 20-40 years
Neat, let’s turn those sizes into a plan.
Timelapse:
Wow, those trees get big at 20 years. In 2043, I will be 63 years old. I wonder if we will still be living here? I wonder if I will still be living? My mom passed away when she was 61, so this morbid thought often crosses my mind. The average life expectancy for women in the US is 81 — which would gain me another 20 years to enjoy my plants.
What about other life changes or preferences? Will I decide in 10 years or 20 years that I no longer like this plant? What about trees that don’t stop growing at 20 years, how many years into the future should I plan?
Improved Tree Symbol
Moderately Fast Growing Tree — Accolade Japanese Cherry
How could I tweak my tree symbol to add more information into my planting plans. I think the landscape architect’s suggestion of a 10 year sized tree as the base symbol makes sense, but I would like to have a little more information about future sizes. I’m thinking a symbol with the 10 year size and the mature size, which for the Accolade Cherry Tree is 20 years.
Let’s see how this looks in plan. It does look more busy, but the additional information about mature size is helpful.
Slow Growing Tree — Autumn Gold Gingko
How about a slow growing tree that does not reach mature size by 20 years?
A tree variety that I am interested in is the Gingko — I want add them along our future pedestrian walkway. I know that there are narrow varieties like Goldspire Ginkgo, but I don’t like their shape as much as a classic Ginkgo like Autumn Gold. The problem with Autumn Gold is that they get huge, but if it takes them 50 years to get so big, does it matter?
I asked ChatGPT to give me Autumn Gold estimated sizes at 10 year intervals:
Ginkgo Biloba — Autumn Gold
Mature Height: 40-50 Feet
Mature Width: 30-40 Feet
10 year Height: 15-20 feet
10 year Width: 10-15 feet
20 year Height: 25-30 feet
20 year Width: 15-20 feet
30 year Height: 30-40 feet
30 year Width: 20-30 feet
40 year Height: 40-50 feet
40 year Width: 30-40 feet
50 year Height: 40-50 feet
50 year Width: 30-40 feet
Years to reach mature size: 20 - 50 years
Lifespan: 1000 years (wow)
If I only cared about the size of a Ginkgo that I planted today for the next forty years (until I was 83 years old), I would want a graphic that showed me the tree size at 10 years up to 40 years.
Neat to see how the Gingko is slow to get started, but then eventually grows pretty big. The Accolade Japanese Cherry will be bigger than the Ginkgo at 20 years, but then stops growing.
This is pretty neat. Now I want a catalog of all of my favorite plants. The next step is to do that?