Garry oak is our only native oak in British Columbia. It is the keystone species of the Garry oak ecosystem, a rare ecosystem restricted to the southeastern part of Vancouver Island and the Gulf Islands. The Garry oak ecosystem has great cultural significance in our region and was traditionally stewarded through indigenous land management practices that included periodic burning. These practices favoured an assembly of plants, e.g. the important food plant camas lily, as well as grasses that attracted a variety of game. Hence, the Garry oak ecosystem is a cultural landscape managed by Coast Salish peoples for millennia before the arrival of European settlers, followed by the disruption of traditional land management principles.
Around Nanaimo, we mostly find Garry oaks near the ocean, e.g. at Pipers Lagoon or Neck Point parks. Harewood Plains and the area around Cable Bay trail also have good-sized populations. In these areas, with shallow soils and severe summer droughts, the trees grow fairly short and crooked. There are a few large trees left on deep soils a bit inland in Nanaimo, e.g. on Fifth Street by University Village mall at the new Tim Hortons, on Northfield Road by the Eden Gardens, and at Milton and Campbell Street near downtown. Most Garry oaks in our region, and the associated ecosystem, have been destroyed due to development and loss of traditional management practices.
The typical crooked outlines of Garry oaks growing on shallow soils near the ocean. Photo credit: Douglas FraserPhoto credit: Douglas Fraser
The bark of Garry oak is rough. Younger specimens (left) have a brownish hue. Older specimens (right) develop deep cracks and a silvery grey colour. Photo credit: Douglas FraserThe thick bark of a mature Garry oak protects the tree from ground fires. Photo credit: Hitomi KimuraThe leaves of Garry oak are shiny, leathery and tough. The shine comes from a thick layer of cuticular waxes, contributing to making the plant drought tolerant by reducing water loss from the leaf. Photo credit: Hitomi KimuraThe leaves are attached to the stem in a spiral pattern. Buds are covered in rusty-coloured hairs. Photo credit: Douglas FraserDeeply lobed, shiny leaf of Garry oak, attached to the stem through a distinctive leaf stalk. Photo credit: Douglas FraserNote how the acorns of Garry oak are rounded and attached more or less directly to the stem. The acorns are edible, but due to their high tannic acid content, they require a lot of processing before being made palatable. Photo credit: Brian Bollman via Flickr
Unfortunately, many of the oaks that you’ll observe in Nanaimo are the exotic English oak, Quercus robur, rather than our native Garry oak. Buttertubs Marsh, e.g., is full of oaks and they’re all English. It can be hard to know which species of oak you’re looking at when you see them on their own. Here are some hints for telling English oak (Q. robur) apart from Garry oak (Q. garryana):
Look at the leaf stalks. On English oak (left) the leaf stalk is almost non-existent, on Garry oak (right), your can definitely put your fingers around the leaf stalk (1-2 cm long). English oak leaves (left) are generally less lobed, smoother, less leathery and lighter-green than Garry oak leaves (right). However, the degree of lobing, texture and colour of the leaves is a more variable trait than the leaf stalk length, and can be difficult to discern when you don’t have the other species to compare to directly.
Look at the stalks attaching the acorns to the branch. On English oak (left), the acorns are attached by long stalks to the branch. On Garry oak (right) the acorns are attached directly to the stem. The shape of the acorns differ too. English oak acorns are slender and bullet-shaped. Garry oak acorns are almost globular. Photo credit: Dan Mullen & Edward Rooks via Flickr
English oak on left, Garry oak on right. Notice leaf stalk length, degree of lobing and texture and shine of leaves. Photo credit: Hitomi Kimura
