Begonias Aren’t Just Bedding Plants

(Originally posted January 3, 2008)

Funny, in the plant world, how one genus can hold some of the most beloved and reviled plants in a single embrace. Begonias are an excellent case in point. If I never saw another “bedding begonia”, aka Begonia semperflorens it would not hurt my feelings. I would not, for one minute, miss them. Ever. You know the ones I’m talking about–planted en masse at the entrance to every apartment complex and shopping center in North America during the summer months–little round “wads” of plant material, crispy around the edges from lack of water or rotting out in the center because the irrigation system continued to run 3 times a day during a solid week of rain in mid-June. And of course they’ve been bred to the point that they are totally without character, each one the same size, the same shape, the same habit–lined up like soldiers in marching formation.

At the opposite end of the spectrum are some truly amazing and beautiful plants–begonias with character. Begonias with big leaves, small leaves, fuzzy leaves, smooth leaves, green leaves, black leaves, leaves that are variegated in a near-rainbow of shimmering, shining and sometimes even metallic color. There are begonias that are only a few inches tall when they reach maturity and begonias that can measure FEET in diameter when they’re well grown. There are even a few that are pushing the boundaries of the hardiness zones and reports of gardeners in Zone 7 and even in Zone 6 who are having success with some of the newer “perennial” types. Several breeders are now working on introducing plants with increased cold hardiness.

Recently, I entered into my “begonia phase”. You know how we are as gardeners–always interested in a vast array of plants of all kinds, but typically with one group taking center stage for a period of time. I’ve been through what seems like a million “phases” in my gardening lifetime and I’ve found that once I get into a particular phase, I never really leave it. I collect until I have a nice supply of plants built up and even though my attention may eventually turn in a slightly different direction, I still add to my previous plant collections from time to time. This is what sets the true “plant nerds” apart from the rest. We never stop. So…my latest “phase” is the “begonia phase”. I’ve already been through the “conifer phase”, the “elephant ear phase”, the “canna phase”, the “dahlia phase”, the “daylily phase” and on and on ad nauseum. A great many of these plants are still with me. Some of have been narrowed down to the very best of the bunch–the ones that perform grandly in the garden every season with the less-than-ideal care that they often receive–but they’re still there. I’m not sure I’ve ever left a “phase” entirely.

So now it’s begonias. But it’s not just ANY begonias that I’m interested in for the current phase. I’ve narrowed it down to some that I can grow particularly well indoors as houseplants during the winter and who thrive outdoors on the screen porch during the summer. Oddly enough, most of them are NOT the flashy “rex” begonias that are so commonly found in garden centers. I don’t do as well with those for some reason. The begonias that have gotten my attention of late are actually species–specifically rhizomatous and fibrous-rooted species, with the fibrous-rooted types taking more precedence. I find that most of the fibrous-rooted species have a better habit–clumping rather than creeping–and that they don’t develop the naked centers that many of my rhizomatous types do as they creep across the surface of the soil. The fibrous-rooted clumpers also tend to stand more upright in their pots and they don’t flop, creep and crawl all over their neighbors.

There are a few species that I have become particularly fond of and that have proven to be tough, resilient, beautiful plants year round with what seems to be a modicum of care. One of these is Begonia nelumbifolia, which, as the name suggests has beautiful, slightly cupped leaves with the stem attached to the leaf at a “center point” as you would see on a lotus. The color is a bright, apple green and during the short days of winter and early spring you may even get a nice show of small, light pink flowers. It also grows to a nice, manageable size for indoors, perhaps 12-15″ tall and 18 inches or so across. A nice coffee table plant in a brightly lit room
Another favorite, though larger and requiring a bit more space, is Begonia popenoei. Its leaves are large–on a well-grown specimen maybe nearing a foot in length from the tip of the leaf to the opposite end. It has a dense, shrub-like habit and is nicely upright. Even so, a happy plant may reach 2 feet tall x 3 feet wide and perhaps more. I have several friends who have used it to spectacular effect outdoors in the shade garden, planted directly in the ground during the summer months where it can reach astounding proportions. It gives the effect of a big, fuzzy-leaved hosta! Then in the fall they dig it, pot it and bring it in to a brightly lit room for the winter where it provides beauty throughout the cold months of the year.

For those of you having a very limited amount of space, not all begonias are giants (though alot of my personal favorites are!). I have fallen in love with the diminutive Begonia coriacea whose mature height is about 6 inches tall, with a spread of perhaps 8-10 inches. Its 2-inch wide leaves are deep olive green and are attached at a center point, much like Begonia nelumbifolia, described above. One of the best attributes of this plant is that during the short days of winter and early spring, it will cover itself in clusters of small, fleshy pink to white flowers for at least two months and sometimes longer.

Another small begonia that I simply adore is Begonia x partita. This is technically a fibrous-rooted begonia, but grows on stems similar to some of the “cane” or “angelwing” types. The stems are thick and swollen–extremely fleshy and succulent–and grow in a somewhat gnarled and almost stunted fashion. This growth habit makes it the perfect subject for turning into a beautiful tropical bonsai. In no time, you can create a small, dense “tree” with a thickened trunk, fat stubby branches, and tiny palmate leaves that look almost like a miniature maple. In addition, during the summer months it will bear multitudes of small, pale pink to white flowers. It really is a little stunner.

Others that I have grown extremely fond of include Begonia macdougallii var. purpurea, a magnificent and fairly large grower with compound leaves that look like those of a Schefflera. The leaves are deep dark green with a purplish-red underside. This is another excellent choice for the shade garden during the summer months where it can truly shine and reach its full, magnificent size. It can also be dug and brought in for the winter and will perform very well as a houseplant. And a new introduction from my buddy Dan Heims at Terra Nova Nurseries called ‘Cathedral Windows’ enjoys a prominent position above my desk where the light from a nearby window can shine through its beautiful leaves. ‘Cathedral Windows’ is a variation on the old-fashioned “beefsteak” begonia with a lighter green and somewhat crested center to each leaf. When the sun shines through from front to back it looks like the stained glass in a cathedral window. And for all intensive purposes it seems to be just as easy to grow as its old-fashioned counterpart!

As far as culture is concerned, the most important thing to remember about the rhizomatous and fibrous-rooted begonias is that they will not tolerate being over-watered. So for those of you who have trouble remembering to water your houseplants, these are the perfect plants for you. Their succulent nature allows them to be very forgiving and in fact, they PREFER to be on the dry side. Overwatering will kill them in short order! They also love to grow in the lightweight, peaty potting mixes that are so popular on the market now. One word of caution: I would avoid the potting mixes that have the water retention crystals in them. They stay too wet and unless you can exercise an extreme amount of self-discipline and lay off of the watering for weeks at a time (especially during the winter months), you’ll drown your begonias in no time flat. For light, bright indirect light is perfect. In a very well-lit and open house, they’ll thrive even without being directly in front of a window. In more closed floor plans with less ambient light, some direct light from a nearby window is beneficial and even a southern exposure will work provided the plants don’t get the direct, mid-day summer sun. Direct sun in the winter is fine.

I feed my plants once a month with a good, organic, water soluble fertilizer–fish emulsion works well, as do others. Just ask at your local, independently owned garden center what they carry along those lines for houseplants. African violet fertilizer works well, too. One last tidbit: I have now transplanted all of my begonias into clay pots. They seem to thrive in pots that have the ability to breathe. Also, the soil in a clay pot dries out faster (beacuse the pot breathes) and if you should get a bit heavy handed with the watering this will help rectify the problem.
So there you have it–my latest “phase”. Who knows what will strike me next, but for right now these begonias seem to have my undivided attention. If you decide to check them out, be careful. Next thing you know you’ll be pushing other plants aside to make way for you newest and latest additions!