PlantFiles: Bur Oak, Burr Oak, Mossycup Oak
Quercus macrocarpa

I planted a Bur Oak in my yard over 4 summers ago and it has done really great. Last year it even grew 2.5'. All I did was fertilize it and no extra water was given outside the rain. That has me a bit perplexed as I had not counted on it outpacing my Swamp White Oak in yearly growth. It gets full sun and has the typical very corky stems of a young healthy Bur Oak. I think regarding the large sized leaves found on the tree in the forest preserve, that has to do with the amount of sunlight it gets. Mine had big leaves after being grown in container fields but the next season the leaves were normal size when having little competition for sunlight. The extreme corkiness and growth are what are unusual. No disease that has attacked many other plants in my yard has ever hurt this tree. I wonder why my oak is doing so much differently versus others in the area. I have to see how long it keeps growing like a madman.

If forced to choose one tree to plant, of all the shade trees, I believe it would have to be the bur oak...

For genetics (it ranges from Manitoba, following the Great Lakes over to Nova Scotia, then spreading west and south through the Midwestern states down to the Gulf Coast in Texas); it is truly a cosmopolitan species, growing in almost all soils and moisture regimes.

For longevity and massive size (living 500+ years if left alone, 75-100’ tall and usually wider than high); it is a giant and a patriarch of woodland and prairie. The national champion resides not far from me, in Bourbon County KY.

For character (the largest leaves and seeds among native oaks, with deeply ridged and furrowed bark); its muted fall colors detract nothing from the boldness of its imposing broad-spreading form.

For utility (casting voluminous shade and creating a wealth of mast); its acorns feed many an industrious squirrel and amuse, as weaponry, children of all ages.

For tenacity (whether the bark is chewed off by livestock and mowers, or the root system is suffocated by parking structures and highways); it takes a long time to succumb to human-imposed indignities.

For humility (prodigiously difficult to transplant, slow to gain height and head, certainly not commercially desirable); if growing trees was meant to be easy, there wouldn’t be a need for the nursery industry and landscape profession.

For nostalgia (there may be taller individuals of other species, but images of the bur oak arise when thinking of impressive specimen trees); among midwesterners, it is the tree many of us grew up playing on and under.

For posterity (unlike lollipop consumer-savvy multi-marketed Xeroxed plastic look-alike clones); a bur oak is one of a kind. It is the tree we plant for our children’s grandchildren: a tree of, and for, generations.

The grand old individuals are slowly passing on, the native haunts are gradually disappearing to development, and it is not a species that will ever frequent your neighborhood garden center. Find that place in your community for a bur oak. The future will thank you.

I have two Bur Oaks in my front yard in San Antonio, TX. Both are fully mature, one about 25 years old, the other about 21-22.

These are beautiful trees with only four inherent drawbacks: 1) Lots of large leaves that shed very slowly over a 6 to 8 week period (good for the compost pile but weekly cleanup is required); 2) Lots of dense shade under the trees which makes growing lawns and underplantings a challenge (the shade is welcome in the summer heat); 3) Prolific producers of very large acorns you can twist an ankle on (good conversation pieces while the victim is lying on the ground and very pretty on the tree); 4) They drop a lot of small branches in the 1/4" to 1" diameter category (just mulch them up with the lawn mower).

I've especially had a problem over the past few years with aphids that seem to love the trees. However, this year I used Bexar Advanced Tree & Insect Control, a systemic treatment applied around the base of the tree near the trunk. I used this on one of the trees in May of this year and it works wonderfully. Kind of expensive at about $18 a quart at WalMart and each tree requires two quarts (its a concentrate). But it was worth it. The treated tree, already infested when it was applied, mostly cleared up and was noticeably greener than the untreated tree. The treatment should be applied annually so I think I'll spring for the $72 and treat both trees in early spring before they leaf.

Even though this is a positive comment, it sounds rather negative. Even with the drawbacks mentioned above, I think Bur Oaks are wonderful additions to any yard capable of handling a large tree. I love mine, would plant them again knowing what I now know and would recommend them to others.

The bark on these trees is grayish-brown, very rugged and somewhat spongy to the touch. This rugged quality adds visual interest in the winter when the trees are bare. The limbs of the Bur Oak are more upright than the more familiar Live Oak. My two trees are on a 61 foot wide lot and don't crowd each other or overhang the neighbors property.

The shade provided by these trees in the summer here in San Antonio where temperatures range between 95 and 100 for almost three months each year is welcome even with the difficulty of gardening beneath. Common St. Augustine grass does fairly well under the trees although not as lush as that grown in full sunlight. Algerian Ivy does well as well as asiatic jasmine, boxwood and a variety of lily we got somewhere. This past spring and summer I planted petunias under one of the trees and it did very well.

I found one of these trees growing in my local forest preserve. What's unusual about it, though, is it wasn't very tall or round, but the leaves on it were HUGE! Each leaf was over a foot long! But the trunk was so skinny! I was doing a report on leaves in 8th grade and took one of these huge leaves to my teacher. She asked me to get her a few more and she laminated them. I don't know if the specimen I found is a freak or what!

~Kristy

This tree can make unusual shapes over time. One tree at my house has lost almost all of its branches on one side and only grows from the other side. Another has leaned over the roof to the west as it struggles to escape a larger (red?) oak. It is more brittle than other trees in my yard, dropping lots of branchlets. But it is unusual and may hawks from a earlier era when it was the only true Savannah tree compare to acadia of Africa. It is fire resistant, having thick bark and a deep taproot that gets water, even in droughts. Its tough leaves makes it harder for animals to graze on, so it is not the first choice for animals to graze on. Also there may had been a subspecies that is more like a dwarf tree or a shrub that resists fires and forms hummocks. I read once in a magnizine that someone has a interest into this form.

I once saw one growing in Scenic State Park in far north Minnesota in poor acidic thin soil that have some sands from eskers. It was rather small and slow growing. Also I heard they grow as far north as Winnipeg, Canada. They are very common in Coon Rapids - the soil is very deep, measuring in the tens and sometimes hundreds of feet and 70 -80% fine sand. In other locations of the Twin Cities, when glacial till replace the sandy soil (glacial till is when you have every type of soil mixed together like rocks of different size, clay, silt and sandy) White oak are more common. So you can tell what kind of soil there is in the Twin Cities by tell what kind of white oak is grown the most frequent.

A great tree personally seen growing as far north as Ashland, WI (Lake Superior).

There are several bur oaks growing in a university research park in my city. They are attractive, slow-growing and long-lived. With their deep tap roots they can withstand drought conditions once established. One thing to remember is to give them sufficient space; they can grow nearly as wide as they are tall.

The Bur Oak is very tolerant of harsh climates. It can handle dry conditions and poor soils. It is a large tree - reaching up to 80' when mature. Foliage is a deep green in summer, but not especially attractive in autumn. Makes a nice shade tree, but plantings underneath require extra care.