Noble Oaks

By Julie Boudreau

If there is a majestic tree in the forest, it is the oak: strong, stretching its branches in all its splendor, while all the others struggle, crowded on top of each other rushing for a parcel of sunlight. When you look through the forest, you recognize them immediately.

The oak is both a proud member of our natural forests, but it is also a widely grown tree in parks and residential areas.  

The Native Oaks of Quebec

In Quebec, there are four native oaks, the most widespread being the red oak (Q. rubra) and the bur oak (Q. macrocarpa). The red oak colonizes many forests which have reached their full maturity and is found as far north as Mont-Laurier, Lac-Saint-Jean and the extreme tip of Gaspésie. A little less abundant than the red oak, the bur oak occupies approximately the same territory as the red oak, even if it is less northern. It is almost non-existent east of Montmagny.

It is not uncommon to come across these two species side by side! They are easily differentiated by the shape of the leaves and the acorn. The lobes of red oak are pointed, while those of bur oak are rounded. Also, the cap of the bur oak acorn, has small fringes. Like a hippie version of red oak!

More difficult to find, there are also some colonies of white oak (Q. alba), as well as populations of swamp white oak (Q. bicolor). The white oak is concentrated in the southwest of the province, with a few occurrences in the Lachute region, on the outskirts of Montreal, then along the Richelieu River, down to the American border and Lake Champlain. The swamp white oak is also scattered along the Richelieu, between Beloeil and the American border, with a presence on and around the island of Montreal.

As we will also see a little later, oaks cross easily with each other. In Quebec, we can thus observe a hybrid between the white oak and the bur oak , which we call the Bebb oak (Q. X bebbiana) and another crossing between swamp white oak and bur oak called Schuette’s oak (Q. x schuettei).

Differentiate the Native Oaks of Quebec

As for the identification of the different species, it may seem easy, but there are often doubts waiting for you! Let us first resolve the case of the red oak which is the only native species in Quebec to have pointed lobes. However, in a park or on the front of a house, several other species have pointed lobes. We must therefore use discernment. We also differentiate oaks by the shape of the acorns. Thus, the red oak has a cap barely placed on the fruit, a bit like a beret.

Our three other oaks have rounded lobes. In the case of bur oak, the sinuses (hollows) are generally deep at the base of the leaf, but almost inexistent at the leaf tip. In white oak, the sinuses are deep along the entire length of the leaf. Then, swamp white oak is barely wavy! It seems simple, but there is a great variability in leaf shapes among these three species, so most of the time we can only assume that we recognize a species!

We will have a better chance of making a good identification by observing the fruits. In the bur oak, the cup is fringed. The acorn of the white oak is elongated. And finally, the cup of the swamp white oak covers about a third of the fruit.  

American Oaks

Even if the number of species growing in Quebec is quite limited, which makes identification pretty easy, the same is not true just a few kilometers from the American border. Our southern neighbours have between 75 and 90 species. Very often, observing the leaves and fruits is not enough to establish the identification of an oak with certainty! You have to fall back on the hair on the underside of the leaves, which can be observed with a small magnifying glass!

So yes. There are many species of oaks in America and the adventure is far from over! Indeed, many species interbreed, which creates, in the natural environment, colonies of uncertain origins. Thus, white oak (Q. alba) crosses with swamp white oak (Q. bicolor), which created the hybrid Q. X jackiana. English oak (Q. robur), native to Europe, crosses with white oak to produce Q. X bimundorum. Finally, by artificially crossing English oak and swamp white oak, we obtain Q X warei hybrids. And so on!  

And Worldwide

The invasion of oaks does not stop at the ocean borders. The European, Asian and African continents also host an impressive number of species. This peaks the number of species in the world at over 450! Interestingly, it’s all happening in the Northern Hemisphere! Oaks are said to be the most important woody genus in the Northern Hemisphere. We are far from this impression when we look at our four glorious native species of Quebec!  

Choice of Varieties for Quebec Gardens

Nurseries offer a remarkable selection of oak cultivars, which makes the options interesting. From this lot, two options: massive trees for large spaces or smaller trees with a columnar shape. Several cultivars are derived from species native to the northeastern and central United States.

In most cases, the autumn colouring is a flamboyant red, but some species opt for coppery brown. Next, particular attention can be paid to cultivation needs, where some oaks have a clear preference for dry, sandy soils, while others live well in flood-prone areas.

• Quercus bicolor (Swamp white oak) H.: 56 ft (20 m) L.: 60 ft (18 m) Zone 4. Average growth. Tolerates salt, pollution and temporary flooding.
• Quercus alba (White oak) H.: 80 ft (25 m) W.: 80 ft (25 m) Zone 4. Slow growth. Develops a taproot. Does not like compaction and does not tolerate poorly drained soils.
• Quercus ‘Chimney Fire’ (Oak ‘Chimney Fire’) H.: 40 ft (12 m) W.: 20 ft (6 m) Zone 5. Columnar habit.
• Quercus coccinea (Scarlet oak) H.: 56 ft (20 m) W.: 50 ft (15 m) Zone 5. Average growth. Tolerates salt. Red coloring in the fall.
• Quercus ‘Crimson Spire’ (Oak ‘Crimson Spire’) H.: 45 ft (14 m) W.: 10 ft (3 m) Zone 5. Columnar habit. Red coloring in the fall. Synonym: Q. ‘Crimschmidt’.
• Quercus ellipsoidalis (Northern pin oak) H.: 56 ft (20 m) W.: 45 ft (14 m) Zone 4. Prefers sandy soils. Does not tolerate flooding.
• Quercus ellipsoidalis ‘Majestic Skies'(Oak ‘Majestic Skies’) H.: 60 ft (18 m) W.: 45 ft (14 m) Zone 3. Red coloring in fall. Synonym: Q. ‘Bailskies’
• Quercus ellipsoidalis ‘Shooting Star’ (Oak ‘Shooting Star’) H.: 40 ft (12 m) W.: 20 ft (6 m) Zone 3. Red coloring in fall.
• Quercus ‘Heritage’ (Oak ‘Heritage’) H.: 50 ft (15 m) W.: 40 ft (12 m) Zone 4. Columnar habit. Synonym: ‘Clemens’.
• Quercus imbricaria (Shingle oak) H.: 50 ft (15 m) W.: 10 ft (3 m) Zone 4. Likes acidic soils. The only non-lobed leaf oak on this list!
• Quercus macrocarpa (Bur oak) H.: 56 ft (20 m) W.: 56 ft (20 m) Zone 2. Grows well at the water’s edge. Likes rich soils.
• Quercus palustris (Pin oak) H.: 56 ft (20 m) W.: 40 ft (12 m) Zone 4. Average growth. Red coloring in the fall. Susceptible to iron deficiency. Does not tolerate alkaline soils.
• Quercus palustris ‘Green Pillar’ (Oak ‘Green Pillar’) H.: 50 ft (15 m) W.: 5 m Zone 5. Columnar habit. Likes moist soil. Synonym: Q. ‘Pringreen’.
• Quercus robur (English oak) H.: 56 ft (20 m) W.: 60 ft (18 m) Zone 5.
• Quercus robur ‘Fastigiata’ (Fastigiate English oak) H.: 50 ft (15 m) L.: 16 ft (5 m) Zone 4. Columnar habit. A great classic.
• Quercus robur ‘Menhir’ (English oak ‘Menhir’) H.: 40 ft (12 m) W.: 13 ft (4 m) Zone 5. Columnar habit. This would be a miniature version of the English oak. Red coloring in fall.
• Quercus rubra (Red oak) H.: 78 ft (24 m) W.: 78 ft (24 m) Zone 3. Tolerates damp soils. Red coloring in fall.
• Quercus ‘Skinny Genes’ (Oak ‘Skinny Genes’) H.: 42 ft (13 m) L.: 10 ft (3 m) Zone 4. Columnar port.
• Quercus ‘Streetspire’ (Oak ‘Streetspire’) H.: 42 ft (13 m) W.: 13 ft (4 m) Zone 4. Columnar habit. Orange coloring in fall.
• Quercus X warei ‘Kindred Spirit’ (Oak ‘Kindred Spirit’) H.: 33 ft (10 m) W.: 6 ft (2 m) Zone 4. Columnar habit. Synonym: Q. ‘Nadler’
• Quercus X warei ‘Regal Prince’ (Oak ‘Regal Prince’) H.: 50 ft (16 m) W.: 16 ft (5 m) Zone 4. Columnar habit. Synonym: Q. ‘Long’
• Quercus X jackiana ‘Admiration’ (Oak ‘Admiration’) H.: 40 ft (12 m) W.: 30 ft (9 m) Zone 2.