Cold Hardy Tropicals

A Tough, Ornamental Evergreen
Mahonia aquifolium is a glossy evergreen shrub native to the Pacific Northwest. It features pinnate leaves on long, irregular stems. The individual leaves are leathery, spiny, and resemble holly. The shrub is somewhat coarse in habit, but is still an interesting and ornamental addition to a cold hardy tropical garden. It will [...]

A bamboo-like shrub with striking foliage
About Nandina Domestica
Nandina domestica, or heavenly bamboo, is completely unrelated to bamboo. Its name comes from its fine, bamboo-like foliage and its cane-like stems. It is an evergreen to deciduous shrub that will grow to 5 feet tall , 3 feet wide, at a moderate rate. Some sources list Nandina [...]

About Camelias
Camellias are evergreen shrubs or small trees with attractive glossy foliage. They originate from subtropical regions of China, Japan and neighboring countries. They are known for their dramatic blooms during the off-season – autumn, winter, or early spring, depending on the cultivar and climate.
Typically, camellias have been grown only in the southern United States, [...]

These tropical-looking plants don’t quite fit into the other categories – small, tropical-looking deciduous shrubs, hardy citrus, eucalyptus, and yuccas. They work well with evergreen trees and shrubs, and deciduous trees to create a permanent framework for your tropical garden.
Dediduous Shrubs, Yuccas, and More:

Buddleia davidii (Butterfly bush) : Zone 5-10
Hibiscus syriacus (Rose-of-sharon) : Zone [...]

Tropical-looking deciduous trees are valuable because they are typically large and easy to grow, creating a framework around which other tropical-looking plants can be arranged. The tropical effect may come from large, exotic-looking leaves; palm-like, finely-divided leaves; or some other feature, such as interesting flowers, fruit, bark, or branch structure.
Deciduous Trees

Albizia julibrissin (Silk tree [...]

Many varieties of trees and shrubs are valuable in a tropicalesque garden for their tropical-looking foliage, flowers, or general habit. Some trees and shrubs are fully hardy, yet add a tropical aura to a landscape. Certain trees and shrubs that have been traditionally grown in warmer areas, such as the southern United States, are [...]