Thursday, 1 September 2011

Back to Blighty

So August is over. While we never quite the blazing skies one hopes for in August, this year has apparently been the coldest in 14 years. Add to that the considerable rainfall - so good for the allotment in many ways - and it's no surprise that the tomato blight has arrived, streaking the stems of the tomato plants with dark blotches. On a verdant, untrimmed plant, the telltale black stems can be hard to spot at first, but when the leaves take on that characteristically sooty look at the edges, it's time for drastic surgery.
 

Every year is the same: I do know that nothing will stop the march of the spores, and that all I can do is to delay the blight's spread, hopefully until some fruit have ripened, but I always find myself unwilling to do what I really should do - remove EVERY SCRAP of diseased material, even if that means uprooting whole plants.
Some people advocate removing all the leaves, so that just stems (blotchy or not) and the immature fruit remain. This seems to hold up the spread of the blight so that the fruit has a fair chance to ripen. I prefer to cut out everything that looks unhealthy, removing fruit to the kitchen to ripen on a windowsill. Last year, the blight hit in mid-September, but the fruits were all very green. I picked them off and laid them out indoors, where they stayed green until the middle of October and then slowly ripened. Indoor-ripened tomatoes are never as good as those which mature on the plant, but home-grown tomatoes in November are a bonus. 
So far, I've dug up the three Razzleberry plants and disposed of them (not in the compost), as the more I cut off the more blackened stems and leaves I found. I've saved the best of the fruit which will hopefully ripen before they rot. The Black Russian plants - which always seem to be the first to succumb to blight - have been pruned back almost to stem and fruit only. The outdoor Sungolds - the one variety that has yielded anything like a crop so far - have had a major trim, and while the greenhouse Sungolds and the Pink Brandywine (miraculously - another variety that is often a blight magnet) show no signs of infection so far, I will be inspecting all tomato plants daily from now on. 
This is the horticultural equivalent of shutting the door after the horse has bolted, of course. There is some excellent advice on preventing tomato blight from taking hold on the Garden Action site, here, which boils down to good garden hygiene, ie, don't unwittingly spread the infection from plant to plant yourself, and also explains why it's a good idea to find a way of watering tomato plants that doesn't involve getting the leaves wet.

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