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 eventually reach 8 feet in height, and will spread out via suckers to reach 3-5 feet in diameter.

It is known as the Oregon Grape Holly due to the bluish-black berries it forms from late summer through autumn, which resemble grapes.

Mahonia aquifolium is hardy to Zone 5, and tolerates a wide range of growing conditions. It prefers rich organic soil but is very adaptable. It can grow in full sun to full shade, in well-drained soil or clay, and tolerates seasonal flooding.

Musa basjoo is generally considered the most cold-hardy banana.

While it does grow in Japan, the Japanese fiber banana is native to the Ryukyu Archipelago, which lies between Japan and Taiwan. It is also very common in parts of China.

Its large, tropical foliage and fast growth rate make it ideal for a dramatic feature in the tropicalesque garden. It will eventually form a large, deep green clump, up to at least 18 feet tall.

Hardiness

Musa basjoo is somewhat unique in that it will actively grow in cool weather. The banana will continue growing until temperatures reach approximately 40° F. It will resist light frost, but die back at 28° F. It is is considered root-hardy to zone 6, and will survive a zone 5 winter with heavy mulch.

Winter Protection

Cut back leaves after soon after light frost damage occurs. Spray the root crown with a fungicide to prevent fungal rot during the winter. Use heavy mulch around the root crown to protect from freezing. Gradually remove the mulch in late winter-early spring as the risk of a hard freeze passes.

Growing Tips

Grow in full sun to partial shade. Musa basjoo thrives on plenty of fertilizer and water during the growing season. It will do well with a regular application of balanced liquid fertilizer applied weekly during the summer. While it is a heavy feeder, be careful not to burn the plant with too high a concentration of fertilizer. Top-dressing with composted manure is another popular feeding method. Leaves may be shredded or dried out in a windy location; pick a site with some wind protection.

Bananas can add an instant tropical look to any landscape. They are fast-growing, with huge, tropical-looking leaves. Although the cold-hardy temperate varieties listed below rarely fruit in colder climates, they are valuable for their dramatic foliage.

Musa basjoo has long been considered the hardiest banana. It should be hardy to zone 6, and it has been overwintered in zone 5 with a heavy mulch.

Musella lasiocarpa and Musa sikkimensis have also been recognized as very hardy, although preliminary trials suggest that they are slightly less hardy than Musa basjoo.

Here are some popular hardy bananas to try growing in your garden:

• Musa basjoo (Japanese fiber banana)
• Musella lasiocarpa (Chinese yellow banana)
• Musa sikkimensis (Sikkim banana)

Certain species of bamboo can survive temperatures as low as -20°F. Below is a list of cold-hardy bamboos compiled by members of the American Bamboo Society. Although the plants will most likely not be killed by the temperatures listed below, they will often die back and regrow from the ground at these extreme minimums. If they experience these temperatures on an annual basis, they may not reach their full growth potential.

Zone 6b Bamboos (-5°F):

• Indocalamus sp. ‘solidus’
• Indocalamus tessellatus
• Phyllostachys mannii
• Phyllostachys nigra ‘Hale’ (Black bamboo)
• Phyllostachys purpurata ‘straight stem’
• Phyllostachys rubromarginata
• Phyllostachys viridis
• Phyllostachys viridis ‘Houzeau’
• Phyllostachys vivax (Running giant bamboo)
• Sasa palmata (Palm-leaved bamboo)
• Sasa senanensis
• Semiarundinaria fastuosa
• Semiarundinaria fastuosa viridis
• Shibataea kumasaca albostriata
• Shibataea lancifolia

Zone 6a Bamboos (-10°F):

• Arundinaria gigantea (Giant cane)
• Arundinaria gigantea subsp. tecta (Switch cane)
• Fargesia dracocephala (Dragon’s head bamboo)
• Phyllostachys atrovaginata
• Phyllostachys aureosulcata (Yellow groove bamboo)
• Phyllostachys aureosulcata alata
• Phyllostachys aureosulcata aureocaulis
• Phyllostachys aureosulcata ‘Harbin’
• Phyllostachys aureosulcata spectabilis
• Phyllostachys bissetii
• Phyllostachys propinqua
• Phyllostachys viridiglaucescens
• Pleioblastus fortunei
• Sasamorpha borealis
• Shibataea chinensis
• Shibataea kumasaca

Zone 5 Bamboos (-20°F):

• Fargesia murieliae (Umbrella bamboo)
• Fargesia nitida (Fountain bamboo)
• Phyllostachys nuda