Tilia americana, or basswood, is native to Ontario with a natural range extending from southeastern Manitoba and New Brunswick, south to northeastern Oklahoma, and east to New Jersey. It prefers moist, fertile, well-drained soils in full sun to part shade, but can tolerate some drought. Typically not as tolerant to air pollution, this tree species is tolerant of a wide range of soil conditions that makes it ideal for residential/gentle urban landscapes. Tilia americana drops a significant number of leaves in the fall and small fragrant flowers in the summer.

Tilia cordata, or littleleaf linden, is a non-native to Ontario originating in Europe and western Asia, but is often planted in North American cities due to its fragrant flowers and tolerance of many urban pressures. It grows well on deep, fertile, well-drained loam and clay soils, with a pH between 5.5 and 7.5. While it generally faces few serious insect or disease issues, Japanese beetles can skeletonize the foliage, so it's best not to plant it in heavily infested areas.

Tilia tomentosa, or white linden, is a non-native species originating in southeastern Europe and western Asia. This species is the most drought-resistant of the linden species and has good tolerance for urban conditions. It prefers a well-draining loamy soil and requires full sun for best growth. It is adaptable to soil pH and has slightly better drought tolerance than other lindens. Lindens typically drop a significant number of leaves each fall and fragrant flowers which attract numerous pollinators in the summer. It is considered moderately messy due to the flower litter and leaf drop that require regular cleanup.

Tilia x euchlora, or crimean linden, is highly tolerant of urban conditions and produces flowers with rich, sugary nectar that attracts bees and butterflies. It prefers moist, fertile, well-drained loams, but adapts to a range of soil conditions. The tree generally experiences few serious insect or disease issues, showing greater resistance to aphids, than other lindens, which reduces the likelihood of honeydew drop and sooty molds. While verticillium wilt can be fatal, it occurs infrequently. Tilia x euchlora drops a significant number of leaves and small, fragrant flowers, with the heaviest shedding in the summer.

Tsuga canadensis, or Canadian hemlock, is native to eastern North American and thrives in well-drained locations. While somewhat adaptable to pH levels, it prefers acidic soil, and cool, moist but typically well-drained conditions. This slow-growing tree grows in light shade and sheltered sunny locations but will not typically thrive when planted in deep shade. Sunscorch and drought can cause significant damage, potentially killing the tree. Healthy trees can withstand the various diseases and pests that are known to impact this tree including leaf blight, cankers, blister and needle rusts, and sapwood rot. The invasive insect, hemlock wooly adelgid is threatening the future of this species in eastern Canada. There are treatment options for trees with light infestations, but untreated trees will typically succumb to this pest within a few years.

Ulmus americana, commonly known as American elm, white elm or Gray elm, is native to eastern North America, ranging from eastern North America, occurring from Nova Scotia west to Alberta and Montana, and south to Florida and central Texas. It is known for its large size, reaching heights of 60 to 80 feet and widths of 40 to 70 feet. It thrives in moist, well-drained clay or loamy soils and prefers full sun to partial shade. Unfortunately, like all native elms, Ulmus america is susceptible to Dutch Elm Disease. For plantings use Ulmus americana cultivars that are Dutch elm disease resistant.

CAUTION: MAY HAVE INVASIVE TENDENCIES. Ulmus glabra, commonly known as Scotch elm or Wych elm, is not recommended to plant, due to its susceptibility to Dutch elm disease. It is a fast-growing deciduous tree native throughout Europe with its furthest northern range in Finland. It thrives in a variety of conditions, preferring full sun and well-drained soils but is adaptable to both dry and moist environments. It thrives in a variety of conditions, preferring full sun and well-drained soils but is adaptable to both dry and moist environments. Once a popular shade tree, due to Dutch elm disease it has stopped being used. An alternative tree to plant is Ulmus hybrids or Ulmus americana.

CAUTION: MAY HAVE INVASIVE TENDENCIES. Ulmus parvifolia, commonly known as Chinese elm or Lacebark elm, is not recommended to plant, due to invasive tendencies. It is a fast-growing deciduous tree native to eastern Asia, specifically China, Korea and Japan. It thrives in a variety of conditions, preferring full sun and well-drained soils but is adaptable to both dry and moist environments. It thrives in a variety of conditions, preferring full sun and well-drained soils but is adaptable to both dry and moist environments. Ulmus parvifolia drops a significant number of leaves and small, winged seeds, with the heaviest shedding in the spring. It is considered moderately messy due to the seed litter and leaf drop that require regular cleanup. It is a common tree of abandoned properties, salty roadsides and disturbed urban areas with compacted soils. An alternative tree to plant is Ulmus hybrids or Ulmus americana.

CAUTION: INVASIVE TENDENCIES. Ulmus pumila, commonly known as Siberian elm, is not recommended to plant, due to invasive tendencies. It is a fast-growing deciduous tree native to Eastern Siberia, northern China, and Turkmenistan. This tree typically reaches heights of 50 to 70 feet with a similar spread. It thrives in a variety of conditions, preferring full sun and well-drained soils but is adaptable to both dry and moist environments. Ulmus pumila drops a significant number of leaves and small, winged seeds, with the heaviest shedding in the spring. It is considered moderately messy due to the seed litter and leaf drop that require regular cleanup. It is a common tree of abandoned properties, salty roadsides and disturbed urban areas with compacted soils. An alternative tree to plant is Ulmus hybrids or Ulmus americana.

Ulmus rubra, or slippery elm, is native to eastern North America, ranging from southwestern Maine to southern Quebec, south to northernmost Florida, and west to eastern Texas. It is known for its large size, reaching heights of 40 to 60 feet and widths of 30 to 50 feet. It thrives in moist, well-drained clay or loamy soils and prefers full sun to partial shade. Unfortunately, like all native elms, Ulmus rubra is susceptible to Dutch Elm Disease. An alternative tree to plant is Ulmus hybrids or Ulmus americana.

Ulmus thomasii, commonly known as rock elm, is a native tree species primarily found in southeastern Ontario, particularly in the Kingston to Ottawa region. Rock elm can also be spotted along some roadsides in the Golden Horseshoe area. It is suitable for sandy, loamy, and clay soils, and prefers well-drained soil. While attractive in form, rock elm faces challenges, particularly from Dutch Elm Disease, a significant threat that also affects other native elms. Promoting the planting and preservation of rock elm where appropriate can help ensure its presence continues in the landscape. An alternative tree to plant is Ulmus hybrids or Ulmus americana.

Ulmus x spp., or hybrid elms, are hybrids of native and Asian species. They are typically resistant to Dutch Elm Disease and phloem necrosis, making them a resilient choice for urban environments. It prefers full sun, and moist, well-drained soils, but will usually adapt to various types of soil and weather conditions. They also demonstrate resistance to pests such as the elm leaf beetle and leafminer. Some cultivars have poor branch attachments, making them susceptible to storm breakage at maturity.

Zelkova serrata, or Japanese zelkova, has a native range that encompasses eastern Asia including Japan, Taiwan, and eastern China. It prefers moist, well-draining loamy soil, with a slightly acidic to neutral pH. It is a drought-tolerant tree that can withstand wind and is resistant to Dutch Elm Disease and elm leaf beetle. This species adapts well to urban conditions and can thrive in both acidic and alkaline soils, though it does not tolerate wet sites. Zelkova serrata drops a moderate number of leaves and small, papery fruits, with the heaviest shedding in the fall. It is considered moderately messy due to the leaf drop and fruit litter that require regular cleanup.