Thursday 10 March 2016

experiments with species gladiolus

I think I am on the verge of success with Gladiolus tristis.  This is a species gladiolus, rather different to the great Dame Edna bunches of hybrids grown for cutting, and according to the Pacific Bulb Society is one of the more widespread species in winter rainfall areas of southern Africa.  My solitary bulb came more prosaically from Avon Bulbs as part of my autumn 2014 order. I potted it up and grew it on in the greenhouse, since turfing a South African bulb straight out into the English winter didn't seem very friendly.  It produced a few rather straggly leaves, and one small flower spike.  I was interested to see them, but in display terms you couldn't consider it a horticultural triumph.

It was destined for the open ground, since I had seen photographs of a clump looking ravishingly pretty, demure pale yellow trumpets hanging gracefully from arched stalks and contrasting well with the silver leaved foliage plants around them.  I rather think it may have been a Christopher Lloyd scheme.  It is supposed to be fragrant as well, though you wouldn't know that from the photograph.  Those books and articles I'd found that mentioned the subject at all cautioned that it was only borderline hardy, but might do outside in the UK given shelter and sharp drainage.  It certainly wasn't doing me any good in a pot, as it looked less than enthusiastic about the whole proceedings and I was always worried about when I should water it or stop watering it, and how I would know when it was time to start watering it again.

Last July I tucked my sad little plant into a corner by the path across the turning circle, marking its position with a short cane.  The leaves soon disappeared, and I wondered if I'd see it again, but this winter a tuft of leaves appeared by the cane.  I thought it was obtuse of it come into active growth through our winter instead of waiting for the spring, but that's how Gladiolus tristis wants to do things.  Now there is a healthy looking clump of foliage over a foot tall, and three flower stalks developing.  The flowering stalks start off by pointing at the sky, then develop a more arching habit as they grow.  The leaves could be confused at a casual glance with Dierama, of which we have a lot in the gravel, but they are ribbed (or rolled) and much thicker to the touch.  The leaves must be hardier than you might expect for something with a reputation for tenderness.  They appear unscathed by the recent frosts, which have burned some of the Watsonia leaves and completely blackened some experimental plantings of Aristea.  It may be that the buds are not so frost tolerant, and that the next freezing night will put an end to them, but so far, so good.

I was right to be anxious about watering and witholding water when it comes to gladiolus.  Surfing the web before lunch I came on a page by somebody called Dave Selinger hosted on the university of Arizona's website, though the opinions are all the author's own, which sets out the cultural requirements of various species, as well as their ability to set seed.  It seems that species gladiolus can be fussy.  Some will abort their flowers and immediately go into dormancy if even briefly short of water during their growth phase, some will tolerate being watered while dormant but others will rot.  I think it's as much by luck as by judgement that I managed to keep Gladiolus tristis going in a pot for as long as nine or ten months.

According to Dave at the university of Arizona Gladiolus tristis is not self fertile, so I fear I will not get seeds from my one original bulb, unless it manages to hybridise with any other species gladiolus growing in the neighbourhood, which is not likely since I think my others all flower later in the year.  Apparently they are a promiscuous lot.

Fired up by the continued survival of G. tristis I potted up my carefully saved envelope of tiny Gladiolus flanaganii bulbs, grown from seed last year.  The consensus on the net is that these definitely do not want to be wet over the winter, so my instinct to take them out of their compost for the winter was probably correct.  They have been repotted with extra sand stirred into the compost to sharpen the drainage.  This species will have red flowers, if it ever gets that far, and in the wild grows on inaccessible cliffs, making collection so hazardous it has been nicknamed The Suicide Lily.

Reading The Pacific Bulb Society's account of where Gladiolus tristis grows in the wild is a reminder that if following the ecological gardening mantra that if you provide the growing conditions a plant would experience in the wild then all will be well, you had better be sure to replicate all the conditions.  Apparently in the wilds of southern Africa G. tristis is found in marshy areas and poorly drained seeps.  I don't have anywhere near enough of it to be willing to experiment with how it does in a poorly drained seep here, but I am fairly sure that in an Essex winter it would rot and die.

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