The Press and Journal (Inverness, Highlands, and Islands)
Plant material hiding deadly surprise
There is a lot going on in the gardening world at the present time and unfortunately not all of it is good.
Let me introduce you to Xylella –quite an exotic name and while it is unlikely to become as well used as Brexit, this newcomer to the plant world is liable to be just as disruptive.
Xylella is a bacterial disease of plants which could become quite devastating if it is not controlled. I would go so far as to say it could become as deadly to plants – not all plants, as foot & mouth disease is to cattle.
I understand from the horticultural press that garden centres are withdrawing from selling plants that host Xylella even when they are available from areas which are known to be free from the disease. The disease comes originally from the Americas and Taiwan but spread to some Mediterranean countries in 2013. It has travelled north to reach France on the European mainland but has not been detected in the UK.
How did it spread across vast oceans? You may well ask! In localised areas it would be spread by insects like Froghoppers feeding on plant sap. They don’t feed over long distances but the insects could be carried some way on the wind. Suspicious minded people like me would suggest that it has spread on plant material!
I would be justified in saying that from past experience. In other words, how did flatworms get to Europe from the Antipodes?
The disease itself has four known sub-species and causes leaf scorch, wilting, dieback and withering as the bacterium invades the water-conducting tissues blocking movement of liquid and nutrients.
This disease has been recorded as attacking vines, citrus, olives, peach, several broad-leaved trees like oaks and plane, oleander and some herbaceous perennials.
Defra, full name Department of Environment, Food and Rural Affairs, with a special responsibility for the plant health of homegrown and imported living plant material, are involved in this situation.
Reports from Defra indicate that Polygala stocks are significantly under threat while rosemary, lavender and members of the prunus family are among other vulnerable species.
I hasten to add that plants in these categories in your garden are NOT at risk however new plant material coming in to this country might be carriers of the disease and here comes the problem.
Vast amounts of plant material is coming into this country on a daily basis which is NOT traded through the traditional outlets where experienced operators would be expected to spot any problems,
I will say no more on that. Quite a number of our well known nurserymen who habitually buy young stock from continen- tal producers, in Italy for example, have declared that they will stop buying from zones where the disease has been identified and in one or two cases growers have claimed they would stop buying stock from the country named.
Just one more outcome of climate change eh?
Let me finish on a brighter note.
One of my favourite bedding plants is Salvia splendens, variety Blaze of Fire. Unfortunately it is not quite so robust as that other favourite, Begonia multiflora Flamboyant and we have certainly seen plenty of that wee chap this summer!
Nevertheless, salvia remains a favourite too and of course it is only one of a family of annuals, perennials and sub-shrubs – one of my favourites being Salvia nemorosa with it’s dark wrinkly leaves and gorgeous violet –blue flower spikes, a neat plant which doesn’t need staking.
But to my point . . .
Wandering round the Dundee Flower Show a couple of weeks ago, I stopped to speak to Brian Young, owner of Holmes Farm Nursery in Ayrshire. Out of the corner of my eye I spotted a striking plant with red and white flowers – Salvia Hot Lips.
I was rather taken with it and then on closer inspection of Brian’s plant display I discovered another four or five Salvias that I had never seen before – crackers, every one of them but then reality struck – they would never survive in our garden in Meldrum, soil too heavy for a start!
Then I remembered what I was preaching to you guys just the other week about half hardy perennials – lift at the end of the growing season, stick them in pots, keep in the cold greenhouse or cold frame over the winter and plant out again next spring.
Trouble is, I didn’t think of that until I was half way home...