On the U.S. Department of Agriculture Plant Hardiness Zone Map, Zone 5 covers a swath from Colorado into the coastal Mid-Atlantic. Small parts of Nevada, Oregon and northern Arizona are also in Zone 5. Temperatures in this zone can drop to -20 degrees F. Some tropical plants can survive in this area, though they may require winter protection, particularly in the coldest part of this region.
Japanese Fiber Banana
Japanese fiber banana (Musa basjoo) is considered the most cold-hardy of all banana trees and is native to the Ryukyu Archipelago, which is between Japan and Taiwan. Also prevalent in China, the Japanese fiber banana is a fast grower with traditional large, oblong leaves that grow in clumps. This tree can reach 18 feet in height.
Though hardy to Zone 5, this tree should get winter protection in the form of heavy mulch. Fungicide may be sprayed on the root crown to prevent rot in the winter. This tree will continue to grow down to 40 degrees F. It can resist light frost but will die back when temperatures drop below 28 degrees F. Plant the Japanese fiber banana in full sun and water regularly.
Northern Sea Oats
Northern sea oats (Chasmanthium latifolium) are clumpy ornamental grasses that resemble bamboo and sway even in a light breeze. Northern sea oats have long, high-arching flower stems topped with silver-green flower spikes. These plants may become invasive. The plant is hardy in USDA Zones 4 to 8 but should be cut back almost to the ground in winter. Leaves will turn brown as the weather cools. These plants thrive in full sun in Zone 5 and require regular water.
Ostrich fern (Matteuccia struthiopteris), which grows best in moist areas, begins as a narrow clump with fronds that will unfurl and become wider, like fountain grass, at the top. Leaves grow on individual stalks with small leaflets alternating sides of the stalk. Hardy from Zones 2 to 6, the ostrich fern will die back in winter in colder regions. These plants can reach 6 feet tall in wet climates and 2 feet tall in areas with less humidity. Plant ostrich fern in partial shade in Zone 5, and provide ample water.