Strength in numbers

Begonia grandis seedlings, early January

This blog post was inspired by plant breeder Joseph Tychonievich, writing for The Garden Professors blog a few weeks ago.  In "Blast from my petunia past", Joseph showed the wide range of seedlings he got in the F2 generations of two different interspecific crosses he had made in the genus Petunia.  In reply to my comment about the importance of growing out large numbers of seedlings he said, "I totally agree — I selected the 9 flowers in each image as the most extreme forms from populations of several hundred seedlings. If you just grew a couple dozen seedling from each of these crosses you’d miss out on a lot of cool things. Breeding is, a lot of the time, a numbers game. The more you can grow, the more cool things you’ll find."

Big Begonia grandis

Begonia grandis in a private garden near Baltimore, Maryland

I'm just back from attending the Perennial Plant Association (PPA) national symposium in Baltimore, Maryland.  I've only recently joined this organization, having been talked into it by my friend Janet Draper.  And I'm so glad she did!  I just spent an amazing, exhausting, energizing 5 days of talks, garden tours, trade show, and best of all, spending time with several hundred fellow plant geeks, including at least a dozen people I already knew from Facebook but had never before met in person.  I took over 500 photos, and it's going to take a while to get them processed and uploaded to my Flickr account.  For now I'll just quickly share some photos of the first plant (of many!) that blew me away: Begonia grandis, a.k.a. "hardy begonia".

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.

Garden Bloggers Bloom Day: August 2014

Okay, enough with the long blog posts for now!  It's time for a quick-and-dirty blog post with pretty pictures and not much else.  These are some of the plants I had blooming in my garden today.  For more information about any of them, feel fee to post questions in the comments section!  For many more photos, click here.  For more Garden Bloggers Bloom Day posts from all around the blogosphere, visit Carol at May Dreams Gardens.


Spigelia marilandica, second bloom after deadheading a few weeks ago


Spigelia marilandica


Asclepias tuberosa, also reblooming after deadheading


Honeybee on Asclepias tuberosa


Clerodendrum bungei, one of my beautiful monsters


Lobelia cardinalis, still going strong


Aralia elata has been dropping tiny white flowers all over everything for a month


When was the last time you took a close look at the flowers of Liriope muscari?


Begonia grandis 'Early Bird', my own early-blooming selection of the species


Hosta plantaginea, "August lily", night-blooming and wonderfully fragrant


Datura wrightii, last night


Datura wrightii, this morning


One more because I can't get enough of those daturas!


Morning glory (Ipomoea sp.), growing as a weed


Sphaerorrhiza sarmentiana (Gesneriaceae), blooming on my windowsill at work

Sometimes, your hybrid just plain sucks

This photo shows a group of begonias from a cross that I thought would be interesting.   I made the cross in 2012, and planted the seedlings in the ground last year.  Despite our coldest winter in 20 years, all 3 seedlings have come back after protection with only a light mulch.

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.

The begonia that broke my heart

Unnamed begonia hybrid, a heartbreaking beauty (June 2012)

I hope to (eventually) blog about some of my successes with begonia breeding, but for now I'm going to describe one of my failures.  The plant in the above photo is one of my own hybrids, photographed in my garden in June 2012, from a cross I made in 2011.  I call it a "beautiful failure" because it ultimately failed several critical tests, and as of 2013 I'm no longer growing it at all.