Begonia update

Begonia hybrid seedlings

Begonias have been a sorely-needed bright spot in an otherwise bad gardening year.  Two cold winters in a row, combined with more than my usual degree of neglect, have taken a hard toll and I've had many losses.  But those losses have opened up some opportunities, bringing more sun into what was an increasingly overgrown garden, and opening up some space to try new plants.  And among the losses, I've had a few pleasant surprises.

Beyond Begonia grandis: new hardy begonias

Begonia grandis, white-flowered form

Many gardeners are familiar with Begonia grandis (a.k.a. B. discolor, B. evansiana, B. sinensis), a tuberous species from China commonly known as the "hardy begonia".  The name is well-earned: this truly is the hardiest species in a huge but mostly tropical and subtropical genus, going dormant in the winter and able to survive freezing temperatures into zone 6.  But for a very long time, the most exciting news about hardy begonias was that they came in white as well as pink.  In a genus with so many flashy plants, neither the foliage nor the flowers of B. grandis are terribly exciting.  The leaves are handsome enough, and the pink or white flowers are nice coming so late in the season... and darn it, it's a hardy begonia.  But hardiness is mostly what it has going for it, and is offset by the thing being downright weedy.  It produces little aerial bulbils that act like seeds, dropping all over to produce a steadily-growing colony that will eventually crowd out smaller and slower-growing plants.

Hardy begonias emerging

Begonia pedatifida showing creeping rhizome and new growth

To most gardeners, "hardy begonia" means Begonia grandis, a tuberous species from China that for years has been considered the only reliably hardy member of this huge but mostly tropical and subtropical genus.  That has changed as recent collections in China have turned up a number of rhizomatous species that are also fairly hardy.  I'm trialing several of these in my zone 7 garden (see But where are all the begonias?) and some of them are already emerging after my area's coldest winter in 20 years.

Signs of life

Begonia pedatifida (late March 2014)

After our coldest winter and latest spring in many years, I went out in the garden this morning and pushed away the mulch from some of my plants, and this is one of the things I found.  This unimpressive-looking little sprout has me excited, because it's a begonia, and it survived my area's coldest winter in 20 years.  This is Begonia pedatifida, a Chinese species that already has a reputation for being fairly hardy but this winter was the real test.  What I find interesting is that the rhizome creeps along the surface of the soil; aside from a bit of mulch this plant had virtually no protection all winter, yet still made it through several nights in the 9-12 degree (F) range and several extended periods with temperatures well below freezing.  This thing is pretty darn hardy.  With any luck I'll have it blooming in a couple of months, when I can attempt some crosses with other begonias.


Begonia pedatifida, leaf (September 2011)


Begonia pedatifida, flowers (June 2012)

And as for my indoor plants, spring can't come soon enough.  I am up to my ears in plants that are ready to go out, and they are overflowing into places where I don't usually grow plants.  Here are some of my begonias, waiting under a table by the back door for a bit of warmer weather when I can finally put them outdoors!