A blight upon your camellias

I married in to a camellia family. Long before the Jury name ever became associated with magnolias, it was known both in New Zealand and overseas for camellias. That is because there were two brothers working independently on camellias in the previous generation.

Les Jury (known here as Uncle Les, for obvious reasons) was the better known and some of his cultivars are classics in the camellia world – Anticipation, Debbie and Jury’s Yellow to name just three. Not far behind was Felix Jury who created Water Lily, Dream Boat, Rose Bouquet and many others.

Encouraged by his father and his uncle, my Mark was following suit. They were heady days and camellias ranked second only to roses in volume of plant sales in New Zealand. Both Mark and I remember the Day of Doom. Mark received an unannounced visit from senior members of the local Camellia Society bringing him the bad news that camellia petal blight had been found in Wellington. It took quite a while for the implications to sink in for me but Mark knew instantly what it meant and that was the day he stopped camellia breeding. Only now, more than twenty years down the track, is he starting to return to it as the picture has become clearer.

From these slightly blemished blooms...

From these slightly blemished blooms…

Camellia petal blight is endemic to China and Japan and has long been a problem on the west coast of the USA. More recently, it has struck the UK and Europe though apparently Australia is still free from it. A plant can’t carry it. It is transmitted on the flower or in the soil. Even back when it was first found in this country, standard practice was to ensure that all plants being shipped in or out of New Zealand were stripped of all flower buds and had their roots washed clean. It is quite possible that it entered this country inadvertently in a corsage somebody failed to discard safely or some similar incident. The discovery of infected blooms in Wellington Botanic Gardens and in two locations in the Hutt (if my memory serves me right) was hardly painted apple moth or Queensland fruit fly territory but its impact has certainly been very disappointing.

... to this in two short days

… to this in two short days

It is a fungus – Ciborinia camelliae, to be precise and the spore are dispersed through the air. The problem in this country is that the camellia is so ubiquitous and the distances from host plant to next potential host so short that the disease spread rapidly. For the same reason, you can’t eradicate it because you will just get reinfected. So we have learned to live with it.

We have always had botrytis which turns blooms dark brown but petal blight is much more rampant. What may be light brown speck on a bloom one day can show as riddled as the pox the following day and pale mush the day after. And it usually hangs on the plant, which is the worst aspect of all because blighted blooms look awful. A lot of modern breeding has been to get camellias that are self grooming – in other words they fall when finished. But not the blighted blooms.

If you want to check that you have it, flip a bloom over and peel off the calyx which holds the petals together in the centre. If it has a telltale white powdery ring inside the calyx, that is petal blight. If it is greyish black, it is botrytis.

The white ring of death - camellia petal blight

The white ring of death – camellia petal blight

Petal blight does not weaken the plant. It merely cuts the floral display. You won’t get as many blooms, though given camellias’ propensity for massive bud set, they will still out flower most other shrubs. You will probably have to do more of a clean up, maybe shake the bush as you pass and rake up the debris to keep them looking attractive. It is still a lot less than many other plants require.

Reticulata camellias (the ones with the huge blooms the size of lunch plates) tend to drop their blighted blooms because they are so heavy. And many are red which doesn’t show the brown blemishes as badly. But reticulatas are very hard to find for sale these days. Despite what some information on the internet says, we have never found petal blight on our sasanqua camelliaseither, and that is not for want of looking. As far as we are concerned they are clean.

The smaller flowered camellias with masses of shortlived blooms in succession are just as good as ever. We had a rush of blood to the head when Mark thought last week that petal blight was entirely absent from his Camellia Fairy Blush (the first camellia he ever named – a C. lutchuensis hybrid, not a sasanqua). He examined many spent blooms and finally found one with the telltale white ring. So not blight free, but unaffected in its display.

It is the bigger flowered, paler varieties that look the worst along with the ones bred for show blooms – fewer flowers but with perfect form. It has pretty well wrecked the traditions of camellia shows. Whether time and renewed efforts by plant breeders can replace these types with blight resistant options is still unknown.

Camellia Fairy Blush - not immune but the display is unaffected

Camellia Fairy Blush – not immune but the display is unaffected

First published in the Waikato Times and reprinted here with their permission.

2 thoughts on “A blight upon your camellias

  1. jaspersdoggyworld

    Very interesting article. I had never really seen petal blight until we brought a house in Avalon in Lower Hutt and all the camellias were riddled with it. Now, we are living in the sunny Mangamahu valley, south of Wanganui and it doesn’t seem to be a problem. Touch wood.

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