“The best time to plant an oak tree was twenty years ago. The second best time is today.”
In America, and maybe most of the temperate climates of the world, I would argue that oaks, Quercus spp. are the kings of the tree world. They certainly are majestic and mighty trees. You probably are familiar with at least one type of Oak, and this tree is considered to be a keystone speciesA keystone species is a species that exerts great influence on an ecosystem relative to its abundance. of a wide range of habitats.
Because Oak trees are so important and there are so many types, I wish to introduce you to some of the general information on them in this article and then highlight some of the species that are best for our gardens, and those which are likely to have a home on our property. I have to warn you that I love Oak trees and might wax a bit enthusiastic. Maybe even insert a soapbox rant or two, but I do hope you come to appreciate these grand trees as much as I do, if you aren’t already of that opinion.
- native to the northern hemisphere.
- deciduous or can be evergreen
- many deciduous species are marcescentnot dropping dead leaves until spring
- prone to high rates of hybridization among their species
- lost in a matter of weeks when struck with Sudden Oak Death (Phytophthora ramorum)
This isn’t about selling you a bill of goods.
Understanding why you should buy and plant Oak trees is about considering future generations, about caring for the earth, and giving definition, at the heart, to what it means to be a gardener.
A gardener is not simply one who plants, or designs, or works in gardens, but one who nurtures their piece of ground and is caretaker of the life of that ground. We never really own the earth, we are simply stewards of it for a time. And planting an Oak tree has a great deal to do with that stewardship.
If it were only the beauty of the Oaks, that would be enough. The great spreading branches of the mighty Oaks that give their shade, their majestic size, their abstract symmetry of leaf and branching, all are reasons enough to plant them as shade trees in our gardens.
Planting oak trees is not a topic often considered by home gardeners, not on the scale of maples, or ginko or other faster growing species, etc. Besides the slow growth of most oak trees, is the sheer size that the oak will ultimately attain. It is the tree of forest, parklands, and very large gardens. Yet, the benefit of an oak is not only its shade properties, but it deeply roots, its leaves break down into rich leafmould, and it is a good neighbor in the garden.Just as with any tree, care should be had in siting it: not too near a building, not where its dropping acorns would be a nuisance, and with plenty of room to grow in a healthy way.
There is more to the oak than meets our eye, or even that comes to our conscious minds, given the strength and beauty of the wood. Let’s think about how oaks fit into our environment.
Oaks Are A Keystone Species
What does that mean, “oaks are a keystone species”?
A keystone species is a species that has a disproportionately large effect on its environment relative to its abundance. ~R.L. Paine
Certain plants play a critical role in the continuance of an ecological community, of a greater impact than might be imagined. Oaks are one of those influential species.
Oak trees support such species as deer, small mammals, and migrating neotropical songbirds in ways that other forest trees do not. 
A Few Facts About Oak Trees
- The leaves and acorns of the oak tree are toxic due to tannic acida phytochemical
- Oaks are wind pollinated, and easily hybridize
- Classification: Members of Family Fagaceae of the Genus Quercus
- Some truffles have symbiotic relationships with oak trees
- Some oaks have persistent leaves which do not drop until new spring growth
- Mature oaks regenerate well after fires
Because the range of oaks is so widespread- there are surely native species where you may live. If living in the Northern Hemisphere, consult with a garden association or a reference book to find the type that thrives in your landscape environment.
Oaks that grow well in Great Britain would be different species than those which thrive in Midwest America (my Ohio garden)!
Some representative species, and named varieties of oak trees to grow (I hope to have a collection of plant profiles to match this list-soon)
- Burr Oak
- Scarlet Oak (Q.coccinnea).
- Red Oak (Q. rubra)
- Pin Oak (Q. Palustris)
- White Oak (Q. alba)
Leaves of the Oak foliage are usually obvoate in shape and lobed; the tree often holds onto them until spring. That quality is termed “marcescent leaves“. Sometimes the leaves are oblong or lanceolate, as in the Shingle Oak, Quercus imbricaria.
Oak leaves illustration
The most colorful of the oak trees is the Scarlet Oak, otherwise oak trees have subtle or dull autumn color in comparison with many North American trees. White Oaks have a purple-red color, Northern Pin have a deeper purple-reddish color, Northern Red Oak become brown-red.
The acorn is the fruit of the oak tree.
‘Acorn’ comes from the Old English ‘aecern’, meaning berry or fruit.
“Large streams from little fountains flow, Tall oaks from little acorns grow.”
Acorns come in a surprising variety, although most have their caps on an ovoid shaped nut. The spiny Burr Oak grows in my vicinity and the acorn gives it its name. Bristly and not unlike the burrs that get caught in our pet’s fur.
Sometimes oaks maybe planted by “nature”, in the guise of busy squirrels who feast on the acorns and are busy gathering them throughout the autumn- a familiar scene in fall.
I think acorns are fun to collect, myself, although not for eating purposes. They make fun crafts, especially if you are partial to Fairy Gardens.
Acorns are somewhat toxic unless they are carefully prepared according to a rather involved process. Most of us aren’t that hungry, thankfully, to need to eat such fare. But it is possible.
For those who wish to know how to prepare acorns for food:Grandpappy’s Acorn Preparation
Plants That Love Oaks
All the rhododenrons and azaleas seem to love the oaks for the deep rotting, the shade they provide and the way the leaves break down into a somewhat acid duff; ferns and heathers like to grow under oaks, for the same reason.
Heucheras, many of the woodland plants like tiarella.
Shrubs such as Symphoricarpos albus, or understory trees like Amelanchier. Remember that many rhododenrons get quite large – almost small tree scale for some of them.
Gooseberry and current fruits, blueberry at the verges, and strawberries as long as the Oaks have high enough branches and sunshine shines in.
Little bitty circles of flowers do not become a grand oak, but a swathe of colorful foliaged heuchera or underplantings of well spaced azaleas create a much better garden picture.
Although it may not produce lots of shade in your lifetime, an oak is a tree with beautiful foliage and shape even while young. Choose some oaks that will give your yard character and lasting beauty, while ensuring future generations of people and wildlife a supply of their benefits.
Where can you find oak trees for sale? I like a local nursery for a number of reasons, but if that isn’t the best solution for you, take a look at the reputable source listed here.
Nature Hills Oak Trees
*Collybia photo by Jason Hollinger