Tomato Blight
Posted by Fiona Nevile in Fruit | 150 comments
We have blight. When we were rushing out yesterday evening I spotted it on three tomato plants. Large blackish brownish splodges and a generally wilty look. It is unmistakeable. We had it five years ago and it devastated our tomato crop within days.
At the time we were creating a website for an expert on plant diseases. The fee was to be paid in whisky. Danny must have negotiated this deal.
The expert arrived with a rather good bottle of Isla whisky under his arm. He was immediately shepherded out to examine the tomatoes.
“Its blight. Just like potato blight. They’re the same family.”
It was hard to discuss his website. We were mourning the loss of a summer plucking sun warmed fruit from the plant and a long winter savouring our intense tomato sauce base. A good harvest makes enough sauce to last us through the winter until June.
We lost our entire crop that year. Now I grow tomatoes in at least two places. The blight has affected the plants at the front on a sunny south west facing wall. Usually the warmth of the wall nurtures the plants but warm and extended wet weather conditions are perfect for the development of tomato blight. I have hoiked out the plants and am hoping the blight spores will not have spread onto the other 12 plants. The blight affected the weakest plants, the others all look strong and healthy. If the wet weather continues for much longer I am afraid that they all will succumb.
The remaining plants could be treated with Bordeaux Mixture which was developed in France to treat fungal disease in vines. A lot of people spray their potatoes with this potion to protect against blight. It is a copper and lime mixture that is not environmentally friendly, so I am loathe to use it on our tomato plants.
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Hi,
This is the first year that I have had my own garden and was quite naive to think that growing tomatoes would be dead easy. A week or so ago I had 15 huge, healthy plants and now every one is dead. (However, my carrots, lettuces, peas and beans have given me wonderful crops)
I have picked off all of the unaffected fruit and stored them in a basket. If they don’t develop the blight and if they never ripen, will they be able to be used for anything? I’m concerned that they may not be ripe enough.
I’ve learned some lessons and will try again next year I guess.
Hi Philip,
Thanks for dropping by and leaving such a useful comment. I found blight on the leaves of a few more of our tomato plants last night and wondered what to do. I will remove the leaves and fingers crossed, may still harvest some toms.
Message from old blighty,
I noticed an infect of blight on my potatoes about 10 days ago and dehaulmed the entire crop immediately . Now my geenhouse tomatoes have succumbed with blight showing on the leaves /that if unchecked will spread to the stems and fruit. there is a glimmer of hope though! In the past when pot blight has appeared if caught when still at the leaf stage of infection if I pull out the haulm by the root collaring the stem at soil level with one hand to stop pulling the spuds up/destroy all the haulms and leave the still buried spuds for at least a week then I have been able to salvage a good number of storable tubers.With tomatoes remove all the leaves up the stem and leave the top (if not affected)to provide some hydrowhatever flow in the plant and It is possible to salvage decent tomatoes. However all plants that show that blight has spread to the stem must be promptly rooted out. I have had success using this method with outdoor toms too —-Philip
How soul destroying, Theo, after all that work.
Hello, I have a 40 ft polytunnell in my allotment, had 4 varieties of tomato, 35 plants, all of them have now got blight, I am devastated, but I still have some chillis in there.
Hi Mark,
Thanks for dropping by. Don’t beat yourself up for planting the potato/tomato combination. They are the same family after all. And the pairing is traditional in the UK.
We have found that germination in the ground has taken ages this year. However, all seed put in the electric propagator have flourished. For the first time , this month, I have tried germinating everything (in small trays that I have transplanted to the kitchen garden when germination has taken place). Everything germinates, I wish I had tried this earlier. You have to cloche when you put the crop outside.
And I thought it was just me – sadly reassuring to see that it’s the British summer contributing to the sudden onset of blight in my tommies – although I’ve not helped much by planting the potatoes next to the tommies and spraying water everywhere.
Have taken all blighted plants out of the polytunnel to incinerated. Have also managed to get a couple of bush tomatoes from Homebase at knockdown prices, just so we can have a few tasty fruit in August – but no homemade pasta sauce this year ….
Interesting to read the comments on courgettes – last year was a bumper crop, but this year I’ll be lucky to get any – cucumbers are doing OK in the tunnel though, and so is the first attempt at sweetcorn
And all the maincrop potatoes are already out of the ground and in storage
Anyon suggest the best way to get parnsnips going ? – I’ve tried 4 times now and they just won’t germinate
Thanks for the update and advice, Kate. Very useful.
Do hope that your greenhouse tomatoes survive. Finally we have a sunny day here, just what the vegetables need.
I picked all the reasonably sized green tomatoes from the blighted plants I destroyed on Sunday, thinking to make chutney. Decided to leave it a couple of days to see if the tomatoes were ok- no, they aren’t, all turning brown and scabby. So, if anyone is thinking of using their green tommies after heaving out the blighted bushes, keep them for a while before using to make sure they are fit to use! I dread to think what the chutney would have been like had I made it yesterday…I agree Fiona, the bushyness of the patio plants made them more prone to blight.Sad to say Michael, if your potato tops are rotten the tubers won’t be far behind, but I suspect the broad beans have rust, mine got that too after a rather disappointing season. My garden is on the slope of a river valley,the air is damp and fungus just loves it, even in a dry year, but this is the first time I’ve had blight.One of the plants in the greenhouse looking a bit sick this morning, so I’ve chopped back as much as possible and fingers are crossed.
Hi Kate,
I reckon that the shrubiness of your patio tomatoes increased the likelihood of blight as the plants would not have dried off so quickly during sunny spells. I reckon cordons are a much better bet. More air circulation.
What a pity about the squash and courgettes. Ours are floundering too. We have one small bell pepper on a plant (we have 4 plants). I was so tempted to grow aubergines this year what a shame that yours are just sitting there.
The one thing I didn’t grow this year were French beans!! So glad that something is flourishing.
Yes, the air must be full of spores. Tomato blight is much rarer than potato blight in a normal summer.
Hi Michael,
Thanks for leaving a comment. Like you, I am struggling to get my head around the problem of blight. If the same happens next year or even ten years later down the line, I want to know that my crops have the best possible chance of survival.
As far as I know Friday’s prolonged rain produced what farmers refer to as ‘Smith’ periods. Minimum temp is 10ºC or higher and at least 11 hours each day when relative humidity is more than 90%. Forecasts are available here http://www.potatocrop.com (the same blight hits tomatoes and potatoes). This site has all the facts
http://www.organicgardening.org.uk/factsheets/dc17.php
I’m sorry but I can tell whether your broad beans have rust or blight. Ours have keeled over too, but they are just brown. I am going to harvest the pods tomorrow. It’s a shame as we had a lot of baby pods but I just don’t want to risk any spores being washed into the soil if it is blight.
Yes you should cot off the stems and leaves of potatoes with blight and burn them. The tubers can be left in the ground for a few weeks if they are not infected. When I discovered that we had blight, I burnt the stems and leaves immediately and dug up the tubers. They looked fine until I washed them. Then I discovered that 25% were brown (not mushy but soft) and infected. So I reckon that leaving them in the ground is probably a bit iffy.
This site is a good forum too
http://www.allotments-uk.com/forum/topic.asp?whichpage=1&TOPIC_ID=4297窝
Hi Dave,
What a shame. Blight is so quick. We couldn’t believe the speed when it first happened to us. I’m sorry but I don’t have the answer to your disinfecting the greenhouse problem. I am thinking of disinfecting my greenhouse with a weak solution of this
http://www.armillatox.com/default.html
I have looked seemingly everywhere and cannot find the definitive answer. I’d love to find a way of killing the spores lurking in the soil in the kitchen garden but as the spores can fly through the air from other gardens it is a problem. Perhaps the answer is to find blight resistant strains?
The rest of your tomatoes will be fine to use. Ripen them on a windowsill indoors. If any are affected they will soon turn brown. If this happens, burn them.