I have written two earlier posts about Begonias in the garden. I’m not referring to the usual bedding types, rather to a range of mainly fairly recently introduced new species that are on the border of hardiness as well as some that would usually be grown as house plants.
My collection continues to grow and with it, my experience of using them as garden plants. My article of 4/10/20 mentioned grandis evansiana, ‘Tie Dye’, ‘Garden Angel’, sutherlandii, ‘Wavy Green’, ‘U614’ and luxurians as varieties I was growing in the garden and to that list I have this year added four more, ‘Torsa’, ‘Connie Boswell’, grandis evansiana ‘Nanjiang Silver’ and ‘Mishmi Silver’. An even earlier post chronicles the very beginning of my journey with begonias.
All have done well, with ‘Connie Boswell’ perhaps suffering a little more slug damage than the rest and ending up not looking great in spite of making good growth. All have been planted in the ground except ‘Torsa’, which is plunged in its pot. I’m still undecided whether to plant it before the winter and leave it out or to bring it back inside for this winter then planting it in the spring. I’ll probably bring it in.
Begonia luxurians is now in its third outdoor season and is around 7 feet tall. It has produced a number of flower panicles, one of which looks like it may produce ripe seed. It is going to be a challenge to lift and pot it again, given its size, but to leave it out is unthinkable, knowing it would not survive. This was the plant that started me on planting out tender types for the summer. It is a treatment that seems to suit it admirably, except that it is very tender and has to be back in before the first frost.
‘Mishmi Silver’ stayed inside last summer and produced very showy flowers late in the year. It is such a handsome plant it really doesn’t look like a wild collected form, more like a classy hybrid. This year it has grown slowly but steadily in the ground, making a superb foliage plant but as yet not flowering. I have now potted it up before we get any cold weather to give it a chance to flower under cover and to over winter. It has robust foliage that hasn’t suffered slug damage but it does seem a bit susceptible to going mouldy if fallen flowers from surrounding plants are left on its leaves. It seems to have an almost prostrate habit that would make good ground cover.
U614 has again grown well and is flowering, with a smattering of small white flowers against its silvery foliage. I collected seed last year and have a few seedlings hanging on, hopefully they will make it through to next spring and grow away, they’re still very small. A piece of the original plant got left behind two years ago when I lifted it to bring inside for winter; it is still going, though it hasn’t grown a lot. It is hardy, inasmuch as it has survived in the ground through three winters, but it is hardly an advertisement for such treatment. The main plant is now 2 feet wide and a real presence in the garden. Sadly, it still seems to be unidentified and unnamed.
Connie Boswell perhaps has thinner textured leaves than the rest and has suffered slug damage throughout the summer. I will lift it and put it back out next year, but perhaps somewhere less shady and damp, in a big pot perhaps.
Begonia grandis ‘Nanjiang Silver’ was late into growth from the tiny bulbils that I had overwintered. Frankly, I was surprised that such tiny bulbils survived through the winter, even in pots under glass, but they all did. By late summer I felt able to plant three out, from 9cm pots and around 6-9 inches tall. They have continued to grow and have produced pretty pale pink flowers freely enough. Bulbils are developing in the leaf axils in almost worrying abundance and are rather larger than last year’s crop. I will leave the planted out group where they are to see if they survive and how well. I have several 9cm pots of it under glass and need to put them in a tray by themselves to catch the bulbils that are beginning to drop everywhere. The ‘Silver’ refers to a very modest amount of silver marking on the leaves, so slight as to be barely worth mentioning, let alone naming it for. I obtained it originally as tiny bulbils from Growild Nursery and must look again at their site to see if they have any others on offer, it being about the time of year for bulbils to be produced.
‘Torsa’ was potted into a five litre pot at the beginning of the growing season and plunged, in its pot, when it was well into growth. To begin with it produced massive leaves, well over a foot across, on very short stems. Later in the summer the stems elongated and flower panicles were produced in the upper leaf axils. The flowers are pink and pretty, but not impressive in the way the foliage is. Like B evansiana (seed parent of ‘Torsa’), the leaves are at their best against the light, with prominent red veins beneath huge pale green leaves.
At this end of the season it is about 3 feet tall and the leaves are just beginning to turn yellow. Large bulbils are being produced in the leaf axils, as they were last year. I pressed these into pots of compost then covered them to about two thirds their depth with grit through last winter. They were very late and erratic to start into growth, with some only beginning to grow in August. I have read advice to press them into compost and leave them outside, at least in frost free areas, something I may try this winter. Covering the bulbils is likely to kill them. They are not true bulbs but nascent tubers.
‘Tie Dye’ was plunged in its pot last year, planted in the ground this. It hasn’t made a lot of difference to its eventual size though it was cut back hard early in the year and only planted after it had made a fair bit of new growth. It has velvety leaves that don’t reflect light like some of the others and combined with its dark colour it probably needs to be positioned somewhere quite light, or amongst contrasting foliage, in order to be seen to good effect. Perhaps a pale mulch material would show it off.
‘Snowcap’ is a fabulous plant and our specimen is now in a 20L tub, standing 28 inches above the pot. It has thrived in a shady spot all summer and is now flowering, as if its foliage were not reason enough to grow it. It is one of several varieties I have that is likely to spend its summers outside, either as a container plant or planted out. ‘Dark Eyes’ is similar in leaf to ‘Connie Boswell’ so may prove not to be tough enough for life outdoors but it will be given a chance to prove me wrong. In pots I can try them in sun or shade, or move them about or group them together. I have several more, which is good; it means I can do another blog in a year’s time, relate another year’s worth of experience with what might be regarded as my latest obsession.
Seeking more information about using Begonias as garden plants, I bought the Kindle version of ‘Down to Earth With Begonias’ by Peter Sharp. He writes of his experience of growing them as landscape plants in Sydney Botanic Garden. The climate there being very different to ours, there are limits to the relevance of some of the content but it has forced me to think about how they should be used to best visual affect, in particular by using decent sized groups. I admit to a tendency to become a collector and to then plant out single plants of lots of different varieties that at least to begin with are out of scale with their surroundings. I need to move on to sorting out a smaller set of really good performers and either growing big plants of them or sufficient numbers to make reasonable sized groups. If I have to lift them for winter then groups of smaller plants may be more practical than very big specimens.
The current focus in the UK, at least as far as using begonias as garden plants is concerned, is on hardy or nearly hardy species and varieties. My experience suggests to me that even for plants that will survive winter outdoors in Cornwall, their performance if lifted and overwintered under cover is so much better, in terms of how soon they are back up and making an impact and how quickly they make decent sized plants, as to make leaving them in the ground seem foolish. The only one for which I would make an exception is B. grandis and its forms. I am on the verge of adding B. sutherlandii to that list and with its easy spread by bulbils, leaving plants out to see how they fare is not a problem. It is possible that ‘Torsa’, which also produces bulbils, will be another.