Native Trees in Ontario That Are Pollinator Powerhouses
Red Oak Tree
Pollinator gardens are all the rage lately, and rightfully so. But while gardeners tend to focus on wildflowers and grasses, some of the most important plants for pollinators can be neglected: trees! A fully functioning ecosystem needs these woody providers. You may be surprised to learn that native trees can be even more important for pollinators than wildflowers in many regions.
Ontario native trees are invaluable to our ecosystems. Our flowering trees provide important nectar sources for bees and other pollinators, often in the early spring before most perennial wildflowers are in bloom. The stunning blooms then become fruits or nuts for wildlife.
On top of that, Ontario native trees are a larval food source for hundreds of species of butterflies, moths, and other native insects. Native trees therefore produce more insect prey than non-native species, and our native songbirds need these insects to feed their hatchlings. Native trees also serve as ideal habitat for Ontario birds and other small mammals. Yes, Ontario native trees support thriving biodiversity all the way up the food chain!
Plus, native trees are crucial to climate change mitigation and adaptation. They reduce urban temperatures, sequester carbon and clean the air by absorbing and trapping airborne pollutants and particulate matter. The shade provided by well-placed trees not only keeps you cooler when outdoors, but can even lower home cooling costs by up to 35% and heating costs by up to 25%!
Ontario Native Trees for Pollinators
These native trees each act as host plants for hundreds of species of butterflies, moths, and other insects. To support pollinators year-round, the list includes spring-blooming, summer-blooming, and fall-blooming native trees. There are also options for clay soil, sandy soil, and loam.
Spring-Blooming
Oak (Querus spp.)
Native oak trees are the most prolific pollinator hosts, supporting over 430 species of caterpillars! Oaks attract several bird species, including jays, woodpeckers, grouse, wild turkeys, and wood ducks. Oaks bloom in spring but produce acorns in the fall, which help support wildlife through the winter.
White Oak, Burr Oak, Chinquapin Oak, Pin Oak, Chestnut Oak, and and Red Oak can thrive in clay soils as well as sand, while Black Oaks prefer sandy soils.
Black Willow (Salix nigra)
Most Ontario native willow species are shrubs, with the Black Willow being our one native willow tree. The most common willow varieties you’ll see across Ontario are non-native species, but our native species act as host plants for 400 species of butterflies and moths and also support 14 native bee species. They are one of the first to bloom in early spring, providing crucial pollen and nectar to pollinators emerging from winter dormancy. Black Willows attract songbirds like goldfinches and yellow warblers. If space is an issue, go for one of the many native salix shrubs, like Pussy Willow (Salix discolor) or Sandbar Willow (Salix exigua).
Willows can thrive in clay, sandy or loamy soils, although they prefer moisture.
Birch (Betula spp.)
Ontario native birch species include White, Yellow, Cherry, and Gray. Like the Black Willow, native birch trees support about 400 species of butterflies and moths. The peeling bark shelters invertebrates and, after it falls to the ground, is excellent kindling for campfires! Birch buds, leaves, and seeds provide food for a variety of birds and mammals.
Birch trees prefer sandy loam, but can tolerate a variety of soil types.
Cherry and Plum (Prunus spp.)
Many species in the prunus family are shrubs, like Chokecherry (Prunus virginiana). While also beneficial, today we’ll focus on tree species including Black Cherry (Prunus serotina) and Canada Plum (Prunus nigra). These trees don’t stop giving! The cherry blossoms in spring are gorgeous and fragrant, providing early nectar sources for pollinators. The blossoms then turn into fruit, delightful for gardeners as well as mammals and birds, including robins, waxwings, orioles, red-bellied woodpeckers, cardinals, finches, warblers and wild turkeys. What’s more, these woody natives serve as host plants for a whopping 450 species of butterflies and moths.
Black Cherries grow best in sandy to loamy soils, while Canada Plum can grow in clay, sand, or loam.
Maple (Acer spp.)
Ontario native maple trees (including Sugar, Silver, Red, Freeman, Black, Manitoba and Moosewood) aren’t just autumn stunners, but support up to 300 species of butterflies and moths. To put this in perspective, the invasive and non-native Norway Maple that is commonly planted in urban and suburban areas supports less than 10 species. Maples also provide important habitat and food for birds and mammals.
Maples can thrive in clay, sandy, or loamy soils.
Wild Crabapple (Malus coronaria)
Wild Crabapple is native to Southern Ontario's Carolinian forest zone and is a host plant for over 200 species of butterflies and moths. The lovely and fragrant spring blooms attract a variety of native bees and other pollinators while the apples provide food for birds and other wildlife in the fall. While tart, the apples can be used in baking, cider or preserves.
Wild Crabapple can thrive in sandy, loamy, or clay soils.
Hackberry (Celtis occidentalis)
Hackberry trees serve as larval host plants for Tawny Emperors, Hackberry Emperors, American Snouts, Mourning Cloaks and Question Marks. The berries attract numerous bird species, including cedar waxwings, orioles, cardinals, mockingbirds, quail, woodpeckers, and robins, and are also edible for gardeners! The fruits continue to feed native birds over the winter.
Hackberries can thrive in sandy, loamy, or clay soils.
Serviceberry (Amelanchier spp.)
There are several native Serviceberry species in Ontario, with tree-sized species including Saskatoon Serviceberry (A. alnifolia), Downy Serviceberry (A. arborea), and Smooth Serviceberry (A. laevis). Canadian Serviceberry (A. canadensis) is a smaller, understory tree or large shrub, perfect for smaller yards. The white blooms in spring are spectacular and provide early nectar and pollen sources for pollinators, while the tasty berries provide food for humans and wildlife alike in the summer. Serviceberries also support 124 species of caterpillars, which will grow into butterflies and moths.
Serviceberries can grow in sandy, loamy, or clay soils.
Eastern Redbud (Cercis canadensis)
This gorgeous understory tree dazzles in spring with bright magenta flowers that attract several species of native bees, including leaf-cutter bees that use cuts from the leaves to construct their nests. Birds like finches, nuthatches, chickadees and cardinals enjoy redbud seeds during the winter. As an understory tree, this is also a great option for smaller yards.
Eastern Redbud trees are adaptable to most soil types, while preferring moist, well-drained soil.
Summer-Blooming
Tulip Tree (Liriodendron tulipifera)
As spring gives way to summer, our pollinators need summer-blooming sources of nectar and pollen, and Tulip Trees provide an abundance! Hummingbirds and native bees, including many bumblebees and long-tongued bees, love visiting its large, tulip-like yellowish-green flowers.
The Tulip Tree prefers sandy or loamy soils.
Basswood (Tilia americana)
The aromatic flowers of the Basswood tree bloom in June and July. Although non-native honeybees love the flowers (and can outcompete native bees), Basswoods also support native bumblebees, butterflies and other insects. The fast-growing trees provide excellent habitat for small mammals and native birds, who also eat its seeds.
Basswood is adaptable and can thrive in sandy to clay soils.
Fall-Blooming
Witch Hazel (Hamamelis virginiana)
Witch Hazel is a small tree or large shrub that is unique in its autumn bloom time (between October-December). Its bright yellow flowers are appealing to small pollinators like hoverflies, gnats and late-flying bees, offering a crucial food source when other flowers are going dormant. The tree acts as a host plant for about 70 species of butterflies and moths, with some nocturnal moths known to visit its flowers.
Witch Hazel trees can tolerate sand, clay, or loamy soils.
Evergreen
Pine (Pinus spp.)
Ontario native pine trees include Eastern White Pine, Red Pine, Jack Pine, and Pitch Pine. These evergreens host about 200 species of butterflies and moths. Pine cones supply seeds for birds and small mammals, and many species of birds, including owls, nest and roost in the dense foliage of mature trees.
Pines thrive in sandy to loamy soil. White and Red Pines are particularly salt intolerant, so avoid planting them near roads or pathways that will be salted in winter.
