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With all the cold weather recently, I thought I'd share some "collectively cool Colocasias", better know as elephant ears.  I wasn't motivated to go outside and take pictures of icicles, deer damage and conifers bending under the weight of snow...  We had a nice turnout of volunteers today with Urban, Rose and Dr. Gredler painting obelisks.  Rose and Urban are working on the large pyramids as Doc works through the smaller obelisks.  Vern came it to start sealing our recently sanded benches.  Larry worked on various projects both inside and out and Bill O. was in later to join him.  We also saw Big John.  I worked on a wide range of tasks and am almost caught up on presentations for the month.  I'm currently ordering our summer tropicals and other plantings which prompted me to think of elephant ears (Colocasia sp. and Alocasia sp.).  Above are two photos of the standard Colocasia esculenta which is still one of my favorites.  We order these as large, grapefruit-sized bulbs which we receive in March.  We then pot them up and keep them warm.  By the time we plant them in the gardens in late May or early June, they've already sprouted up to about 18" or so.  They end up being 4-5' tall and larger depending on the watering and fertilizer we provide.  The copper cheese vat planter above has three of these and they were huge (plenty of TLC).  We find that this species does fine in part shade and even gets larger leaves in dappled light.  However, the more colorful varieties have maximum appeal in full sun if possible.  Keep elephant ears moist and in rich soil and you wont be disappointed.  We use supplemental fertilizer once every three weeks from June through August to give them even more of a boost, particularly in containers.  
When I started at the gardens many years ago, we only grew the standard species mentioned above.  In the past decade though, the breeding of this popular tropical has been aggressive and there are so many neat cultivars available on the market.  There are lots of new varieties from Dr. John Cho of the University of Hawaii.  Most new varieties are not purchased as bulbs however, they are tissue cultured "starts" that have rooted and can be directly planted in the garden or "up-sized" to a larger container.  Winter storage for elephant ears can be tricky for those that have not yet formed bulbs although those with bulbs, can be dug, dried and stored in October like you would cannas or dahlias.  We try and overwinter our fancier elephant ears in a greenhouse setting to keep them going with just enough heat and water.  We've had mixed results but do try to perpetuate our favorites over the winter.  As I found and added photos to this blog, I realized quickly that this is just a smattering of varieties that I've photographed and certainly doesn't do justice to this durable tropical that thrives in our Wisconsin summers.  Varietal listings are under the photos below.
[Image] Royal Hawaiian 'Black Coral' [Image] Royal Hawaiian 'Hawaiian Punch' [Image] Royal Hawaiian 'Blue Hawaii' [Image] Royal Hawaiian 'Maui Gold' [Image] 'Black Magic' [Image] 'Heart of the Jungle' [Image] 'Elena' [Image] 'Midori Sour' [Image] 'Mojito' [Image] 'Coffee Cups' [Image] 'Coffee Cups' [Image] Royal Hawaiian 'Diamond Head' [Image] Royal Hawaiian 'Diamond Head' with Dichondra 'Silver Falls' [Image] 'Illustris' [Image] 'Illustris' [Image] Colocasia gigantea 'Thailand Giant' [Image] Colocasia gigantea 'Thailand Giant' [Image] Unknown variegated variety at Frederik Meijer Gardens (Grand Rapids, MI), Conservatory