A new hardy begonia?

Unnamed begonia hybrid (August 2014)

I'm leading with a photo from last summer because that's what this blog post is ultimately about.  And hoo-boy, could I use some warm weather right now!  This has been a slow winter for me, with MANTS being an isolated bright spot of horticulture in the middle of January (see Beating the winter blahs at MANTS).  This hasn't been a bad winter for Washington, DC but I'm just back from an extended visit to Buffalo to help out with my dad, who is in a nursing home following a major stroke and was in the hospital for the last 6 days of my latest visit.  This was an exhausting visit, and to add insult to injury the weather was awful but for once it worked in my favor: there was a weather advisory on the day of my scheduled departure and I was able to extend my stay for an extra 3 days without any additional fee.


Snowy Buffalo sunset

What a relief to finally come home from the cold and snow!  The first thing I did, as I always do upon returning from a long trip, was to check on all my plants.  I was happy to see that many of the seeds I had sown before my trip are germinating well.


Begonia seedlings

But one begonia in particular has me a bit excited!  Last fall I left several potted begonias, both species and hybrids, on my back steps after frost knocked them down.  Before heading out of town for Thanksgiving I covered them with leaves, intending to bring them in upon my return and before the weather turned much colder.  Well, the holidays are always a crazy time for me; fast forward to 2 weeks ago and that's when I finally rescued them, just before my trip to Buffalo.  While they were still outdoors, lows went down to the low twenties (ca. -5° C) several nights, with at least one night near 10° (-12° C) and a couple of periods that stayed at or below freezing for several days.  I fully expected most to be dead, but when I pulled away the leaves I was encouraged to see that several still had firm rhizomes.  I placed them in a cool room and left for Buffalo.


Dormant begonias

I've discovered that many begonias are surprisingly hardy, and will survive extended cold periods as long as the rhizomes don't freeze solid (see Beyond Begonia grandis: new hardy begonias and Hardy begonias: the next generation).  Although these plants were in pots, the sheltered concrete steps and leaves apparently gave them sufficient protection when temperatures dropped well below freezing.  When I came home I checked on them, and was pleased to see that most still have firm rhizomes and look like they're going to survive.  But on looking even more closely, I saw this:


Signs of life

And that brings me back to the begonia in the photo way up at the top.  Yes, this is the same plant, and it's not only still alive but is already putting out new growth.  Here's another look at the plant last summer:


Unnamed begonia hybrid (scale: 5"/12.7 cm pot)

This plant, one of my own hybrids, has a spotted form of B. formosana as one parent; the hybrid's leaves are darker, and more heavily spotted, but otherwise it's similar to that parent in size, growth habit, and leaf shape.  Both form creeping rhizomes at or slightly below the soil surface, from which grow upright leafy stems.  Begonia formosana has been hardy for me through two winters, surviving temperatures in the single digits (ca. -15° C) with only light protection.  The other parent (a complex rex hybrid with B. deliciosa in its parentage) has also been hardy in the ground for me, and I'm pleased that my hybrid has apparently inherited hardiness from both parents.


Begonia formosana (with seed capsules of B. grandis)

I got several nice seedlings from this cross, and in addition to the one I kept in a pot, I planted two of them in the ground last year.  It will be interesting to see whether they come back this spring; if they do, I think I might be onto something!  Maybe it's time to start thinking of cultivar names... any suggestions?