- In U.S. Department of Agriculture plant hardiness zone 3, average annual low temperatures reach minus-40 degrees Fahrenheit. The fringe tree (Chionanthus virginicus) is hardy in zones 3 to 9. It grows slowly to 20 feet tall with an equal spread and has an open crown. Fringe trees produce pendulous clusters of aromatic white flowers in spring. They prefer sun to partial shade and well-drained soil. This deciduous tree tolerates urban pollution. The winterberry holly (Ilex verticillata) grows slowly to 15 feet tall with a 10-foot spread. This deciduous tree is hardy in zones 3 to 9 and tolerates urban sites, wet to dry soil, and sun to partial shade. It produces white, bird-attracting flowers followed by clusters of red berries in fall and winter.
- To thrive in USDA zone 4, trees must tolerate temperatures to minus-30 degrees. The star magnolia (Magnolia stella) is hardy in zones 4 to 8. It grows slowly to 20 feet with a 15-foot spread and has light green leaves that turn yellow to copper in fall. This deciduous tree prefers full sun and tolerates a range of soils. It blooms with aromatic, white flowers from late winter through early spring and is frost-sensitive. The eastern redbud (Cercis Canadensis) is named for the red-purple buds it produces in early spring before blooming with pink blossoms. Eastern redbuds are hardy in zones 4 to 9 and grow to 30 feet tall with a slightly wider spread. They prefer sun to partial shade and tolerate drought and a range of soils.
- In USDA zone 5, lows reach an average of minus-20 degrees. The goldenchain tree (Laburnum anagyroides) is hardy in zones 5 to 7 and grows slowly from 12 to 30 feet tall. This deciduous tree has a narrow, 9- to 12-foot spread and blooms with long, hanging clusters of yellow flowers. It prefers sun to partial shade and tolerates a range of soils, but does not tolerate heat. The Little Gem magnolia (Magnolia grandiflora "Little Gem") grows to 20 feet tall with a 10-foot spread. This slow-growing evergreen is hardy in zones 5 to 9 and grows well in sun and a range of soils. It blooms with white, aromatic blossoms in summer and has dark, leathery leaves.
- USDA zone 6 experiences average lows to minus-10 degrees. The sorrel tree (Oxydendrum arboreum) is hardy in zones 6 to 9. It grows to 30 feet tall with a 15-foot spread and has drooping branches. Its deciduous leaves turn purple, red and yellow in fall, and it produces fragrant summer flowers that attract pollinators. Plant the sorrel tree in sun to partial shade and well-drained to dry soil. The tall stewartia (Stewartia monadelpha) is hardy in zones 6 to 8 and grows to 25 feet tall with a similar spread. This rounded tree has deciduous foliage with deep red fall color. It tolerates heat and thrives in sun to partial shade.
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