Plant Palette

Plant Palette

Paperbark Maple-- Acer griseum

Photo of Jennifer Schultz Nelson

Jennifer Schultz Nelson
Extension Educator, Horticulture
jaschult@illinois.edu

Plant lovers will not think it strange when I say that when I first saw a paperbark maple, it was love at first sight. My first encounter with the paperbark maple was in graduate school at the University of Illinois at Urbana-Champaign. Like some cheesy romance novel, I saw this particular tree near Bevier Hall a few times a week, fell in love with it, and didn't even know its name.

Later I learned that this tree was a paperbark maple, Acer griseum, a tree native to central China. The tree I had loved near Bevier Hall was slated to be moved to make room for new construction. This was no small feat, as the tree easily stood twenty feet tall and its branches reached at least fifteen feet across. Paperbark maples grow very slowly, so a specimen this large was worth trying to save.

A few of my classmates and professors and I regularly checked on the process of moving this prized tree. The root ball was enormous! I got to climb down in the hole to check it out first hand. It was taller than me, which is not all that tall for a person, but very tall for a root ball.

The day came for the big move, and we watched a large crane attempt to move the tree out of its hole. At first the tree wouldn't budge, but the crane started to come up off the ground! Eventually the crane operator was able to move the tree from its hole to a flat bed truck.

The tree was transported to its present location north of the Ag Engineering building, planted and carefully monitored. So far the tree appears to be happy in its new home.

Why do I love this tree so much? Well for one, it is absolutely beautiful. What struck me first about this tree was the bark, from which it gets its name. The term "paperbark" refers to this tree's exfoliating orange-red bark, much like that of a river birch tree.

The tree also has an outstanding form in the landscape. It may be grown as a multi-stemmed or single trunk specimen, but either way it has a very pleasing rounded shape. This outstanding form paired with the orange-red exfoliating bark is particularly striking against snow in the winter.

The leaves are compound and composed of three leaflets, making the leaves seem differently shaped and smaller than other maples at first glance. If you overlap the edges of the leaflets and trace the outer edge, the shape will resemble what we traditionally recognize as a maple leaf. The paperbark maple is one of the last trees to turn color in the fall, typically a shade of red.

The paperbark maple makes a fruit called a samara, as do other maples. I grew up calling these "helicopters" --our silver maple trees produced thousands. I know the correct term, but I still think "helicopter" when I see them, even on the paperbark maple.

Unlike other maples, most of the seed produced by the paperbark maple is sterile; they are incapable of growing. Botanically this is called parthenocarpy, which means the plant produces seedless fruit. So the good news is that you won't spend hours yanking up paperbark maple seedlings from nearby flower beds, unlike other maples which sow thousands of seeds which germinate quickly everywhere you don't want them.

However, this lack of viable seed is what makes paperbark maples very difficult to propagate. Only 1 to 8% of seed is actually viable-- able to produce a seedling. Of those seeds that do germinate, there is a high level of seedling mortality. So a lot of work goes into getting a few good seedlings.

Propagation by cuttings is the primary method of producing trees for the nursery trade. Far fewer are produced via seedlings, or by grafting onto other maple rootstock.

This difficulty with propagation contributes to the high price tag on paperbark maple, but so does its slow growth rate. It will reach a height of twenty to thirty feet, but takes many years to do so. A relatively small paperbark maple tree is likely to be a lot older compared to faster growing species. Each year that a tree must be cared for in a nursery adds to its cost to the consumer.

We learned the hard way that paperbark maples will tolerate a wide range of soil types, and prefer moist well-drained soil, but there is a fine line between moist and too wet. Our first paperbark maple was planted right before we sodded our yard, and it was a goner after the heavy watering required by newly laid sod.

Our second tree seemed to have a better shot at survival. We planted it in the early fall, it looked great, then the ice storm of 2006 hit. After that storm I found the tree laying on the ground; the stakes we had strategically placed to brace the tree against the high winds typical at our house had broken in half. I carefully re-staked the tree and crossed my fingers.

The tree leafed out the following spring, but died shortly after leafing out. I dug it up to try and do a plant autopsy. One side of the tree had no roots. It was not that the ice storm had broken the roots, there were no roots to begin with. That explained why the tree fell during the ice storm. It had no roots to hold it in place! Even if the ice storm hadn't toppled it over, its days were numbered.

Figuring the third tree had to be a charm, we bought a container grown tree rather than balled and burlapped, simply because it was much more affordable. Although the tree was much smaller than the previous two, it is thriving today. I don't think its survival had anything to do with it being in a container vs. balled and burlapped, but I'm much happier with a small tree that is alive than a big dead tree in my front yard!

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