Written by s • How Big Does That Tree Really Get?

I was talking in a previous post about planting trees with the future in mind, and some thoughts on how to have a better chance the tree you plant today will reach its natural maturity next century. Perhaps the most important thing is to have enough room for it, since nothing spells the likely end of a tree more than becoming a hazard, overhanging a building, or crowding a small lot.

One issue when choosing trees is the tendency to underestimate their ultimate size, making it more likely they will run out of room. A lot of websites, and even books, tend to underestimate sizes. This isn’t so bad with dwarf evergreens, where it is notoriously bad. The difference between a Bird’s Nest Spruce you expect to be 2 feet across and the result after 20 years, when it is 10 feet across and 6 feet tall, is big, and can be annoying. But the difference between a tree you thought would reach 30 feet and the tree that will one day be there, 100 feet tall and very wide, is big enough to cause a problem! So in this post I thought I would talk about, and illustrate, just how big popular tree really can become. Not only are these ‘Monumental Trees’ awe-inspiring and remarkable, they do show us just how large trees can be, given enough time.

We read accounts of the original old-growth, never-logged forests of America, long gone, perhaps forever. When we see these remaining large trees we get a glimpse of what it must have been like to step off a boat and see them stretching across the country as far as you could travel.

I am going to skip the most well-known really big trees, those over 100 meters (325 feet). These include trees like the giant redwoods, Douglas Fir and Sitka Spruce, all of which grow best only on the West Coast. Instead, let’s look at trees that are more easily and widely grown, even if they don’t get quite that big, or break the magical ‘100m’ boundary.

Ponderosa Pine

Pines are some of our best native trees, and Pinus ponderosa is an easy and reliable tree, growing rapidly when young. It can add 18 inches a year, and thrives in most well-drained soils, tolerating cold, a significant amount of heat, and coastal salt-spray too. We suggest a final size of between 60 and 125 feet, which is a fair estimate in most situations.

The biggest Ponderosa Pine, though, and actually the tallest pine in the world, is this one – the tree on the left.

The picture shows Will Koomjian, the arborist who discovered it, and climbs trees like this for fun, transferring from the tree on the right, to the left tree, after he realized it was bigger than the one he was already on. He is 200 feet above the ground.

The tree is in southern Oregon, growing in the Rogue River-Siskiyou National Forest. It measures 268.3 feet tall, using a laser, but part of the point of Will climbing it was to drop a tape, and get a guaranteed size. It turned out to be exactly the same as the laser. That is one big tree, and surrounded by many others of a similar size. A lot bigger than our listing of half that, but hey, it’s going to take a while before yours catching up, so we are probably OK listing this tree at 125!

Actually, that tree was measured in 2011, and since then one almost 6 feet taller has been found outside Sonora, California, in the Sierra Nevada. But you get the idea. . .

If you live in cooler parts of the east, then you perhaps already know White Pine, Pinus strobus, an iconic tree of the Great Lakes. They get pretty big too.

Here is one in the Great Smokey Mountains. It is 187 feet tall, and known to have been seeded in 1845. So it’s pushing on to 200 years old. When you plant a White Pine, who knows what will be going on around it in 200 years? Those old timers had confidence in the future, though, when they planted. That’s something we need to recapture in our present times of uncertainty, and spreading despair.

If you don’t have room for a tree like this, plant the Dwarf White Pine instead – it’s a great little miniature tree for every garden.

The biggest trees are all conifers – evergreens to most people. But some of our deciduous trees get big too.

Actually, the biggest are not native, they are gum trees from Australia. The biggest are Eucalyptus globulus, the Tasmanian blue gum. Here are a couple in Balboa Park, California. They are 140 feet tall. Planted around 1900, they are relative youngsters, and could perhaps have been planted by your grandfather. It shows that just a few generations are needed to produce outstanding trees.

One thing to notice with especially deciduous trees is how much their growth is influenced by environment. They grow their tallest when in a forest, as they compete for light and push upwards. When planted in the open, say as a shade tree or in a park, they grow large, but nowhere near as tall.

Red Oak

The red oak, Quercus rubra, is a popular tree throughout the east. The tallest, 130 feet tall, is this one, growing in forest in Kennett Square, Pennsylvania.

Trees growing in the open won’t ever be this tall, but they will become broad and spreading, and in many ways more dramatic. Maybe this one is a bit close to the house?

Pignut Hickory

Carya glabra, a native hickory tree, is a long-lived and handsome garden tree, which nuts that feed local wildlife, and outstanding golden fall colors. We list it as growing to 80 feet, but the record is 148 feet, but again, that is in a forest, pushing up for light. Here is a tree at the Morton Arboretum, growing more in the open.

American Sycamore

This is another iconic tree. Here is one in Pennsylvania, planted in 1750. This has been taken with a wide-angle lens, to fit the tree in, but it does reduce its grandeur a little. This tree is 120 feet tall, and the trunk is 30 feet around, at ‘tree hugging’ height. Record trees in forests are approaching 150 feet, but they won’t be as impressive as this one growing in the open.

Time to Get Planting for the Future

I hope this quick and random tour of some of our biggest trees will inspire you to find a way to plant some of our forest trees for the future. While America cuts down many trees, it has planted more than that each year, since 1997, so we won’t run out of forest. It is other heavily-forested countries that need to get planting. Of course, these doesn’t replace the old-growth we have, which should be actively preserved wherever possible.

All that aside, planting at least one tree is something everyone should do. Most of us leave little or nothing when our time is up, so let’s all at least leave a tree behind. Make it a nice one.