If you’re lucky enough to have Garry Oak trees on your property, you’re caring for a piece of a disappearing ecosystem.
Victoria and the southern Gulf Islands are the only places in Canada where Garry Oaks are found. Garry Oak ecosystems are one of the three most endangered ecosystems in Canada – less than 1% remains compared to 150 years ago. Almost no ‘intact’ Garry Oak ecosystems remain in Canada. Even in areas where there are still oak trees, many of the associated wildflowers and native grasses have disappeared – which also means that the butterflies, moths, reptiles, and birds have also gone.
But you can help bring them back through a few simple activities!
Key principles of caring for Garry Oaks are rebuild the soil, and control invasive weeds. This will encourage native plants and improve the health of the oak trees. Then you can enjoy your beautiful, low-maintenance native wildflower meadow!
- The soil surrounding our remaining oaks is usually poor and compacted. By rebuilding healthy soil, you are returning nutrients, improving moisture retention, and creating the right germination sites for native plants.
- Leave those leaves! Oak leaves are natural mulch that restores and builds soil. Simply let your oak leaves lie where they fall, or place them in a deep layer around your oak trees and throughout your meadow.
- Camas, Fawn Lilies, and other native bulbs will have no problem sprouting up through the mulch layer.
- Pile those leaves deeply around your trees. A thick layer – even up to 30 cm thick – will decompose quickly and, over time, become healthy soil. It will also smother out invasive weeds like orchardgrass and blackberry.
- As the soil improves and weeds decline, your native flowers will thrive! Reduced competition from turf grass will improve the health of your oak trees, too.
- To speed up decomposition of the oak leaves, make sure they’re slightly moist. You can also pile in a wire cage and keep moist. Oak seedlings will sprout in the pile.
- Invasive weeds are a severe threat to Garry Oak ecosystems. Scotch broom, blackberries, and introduced grasses smother out native flowers and shrubs in open, sunny areas. English ivy climbs up the trees, killing them with the weight and competition for light.
- Weed-whack that blackberry, pull that broom! By removing invasive weeds, you’ll be creating space for native plants and improving habitat for birds and other wildlife. Always remove young or solitary weed plants, before they grow into serious infestations. Contact HAT for tips on effective weed control.
- Remove ivy now! Work first at eliminating ivy that is already on your trees. Cut the ivy stems as close to the ground as you can. Then, cut them again about 1 m higher. Remove all of the stems clinging to the trunk, working your way around the tree to make sure you’ve created a gap. This gap will help you to see, and remove, new ivy shoots spreading up the tree.
- After you’ve cut all the stems around the trunk, leave the climbing ivy branches that are wrapped higher around the tree. They will die and dry out. Once they start to rot you can easily pull them down without damaging the oak tree. It may take a year or two for the ivy to die if it has become established in the tree’s upper branches.
Leaf a Legacy
Protecting Garry Oaks for the future will take more than nurturing the trees we have – we also have to ensure there are young trees to replace the magnificent mature ones that remain.
When you pile your oak leaves, you’ll notice dozens of acorns sprouting into seedlings. Leaving one or a few oak seedlings to grow and flourish will help ensure your children and grandchildren can enjoy our region’s unique natural heritage, Garry Oak meadows.