After three years of researching, I've come up with a list of my favorite plants that can help transform your backyard into a tropical oasis. First list is of tropical looking plants. The second list is evergreens that will give your garden winter interest.
Tropicalesque plants
Musa Basjoo
Musa Sikkimensis
Phyllostachys bissetii
Phyllostachys aureosulcata
Sasa Genus of bamboo
Indocalamus tessellatus
Fargesia dracocephala 'Rufa'
Magnolia tripetala
Magnolia grandiflora 'Edith Bogue'
Magnolia fraseri
Magnolia macrophylla
Petasites japonicus
Canna musafolia
Your favorite hardy ferns
Your favorite hostas
Your favorite Iris
Paulownia tomentosa
Hibiscus Fireball
Asimina triloba
Kniphofia northiae
Catalpa
Albizia julibrissin ‘Rosea’
Desmanthus illinoensis
Impatiens omeiana
Arisaema consanguineum
Aesculus
Astilboides tabularis
Figs
Hakonechloa macra
The Broad leaf Evergreens
Daphniphyllum macropodum
Ilex glabra
Ilex crenta sky pencil
Ilex pedunclosa
Viburnum pragense
Viburnum rhytidophyllum
Aucuba japonica
Trochodendron aralioides
Magnolia virginiana moonglow
Magnolia grandiflora ‘Bracken’s Brown Beauty’
Pieris japonica
Kalmia latifolia
Disporsis pernyi
Asarum europaeum
Hedera helix 'Prince Avenue'
some Epimediums
There are many others too. These are just the ones I've researched and like the most. I hope others living in the rather boring USDA Zone 6 find this useful. And please feel free to add to my list. I'm always looking for new plants to try!
