Fighting the dreaded blight
Posted by Fiona Nevile in Vegetables | 23 comments
Photo: Greenhouse green tomatoes
It’s that tomato blight time of year again. I put on my strongest spectacles and carefully examine all my tomato plants morning and evening. This can take some time as we are growing over forty plants in the green house and various corners of the garden. If ignored the blight will spread rapidly, given the right conditions.
But if you have time on your hands and are diligent it is possible to keep blight at bay if it’s discovered in the early stages.
The greenhouse plants have suffered more than the outdoor ones this year. Mainly my fault as the planned cordons raced away to become bushes and created a superb rainforest environment. The peppers, chillies and cucumbers are loving it. But the tomatoes are struggling.
The greenhouse is well ventilated and I’m keeping the door open all the time at the moment to increase the circulation of air. But each morning the tomato plants are dripping wet with condensation.
I cut off any infected leaves and fruits and burn them. This does give the plants a bit more air and a better chance of not succumbing to the dreaded tomato blight. I managed to keep blight at bay the summer before last using this method on outdoor toms but it’s very laborious. This morning I spent an hour in the greenhouse battling the blight and filled the dustbin burner with iffy leaves.
Until last year Bordeaux Mixture was considered a good organic solution for tomato blight, I am wondering whether to go down this route. For potatoes it is used as a preventative and as a treatment for tomatoes.
Editing the photo above I spotted some blighty foliage in another part of the photo so I’m off down the garden in my pyjamas to snip it off the offending leaf.
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Hi Suzanne
I have never made my own Bordeaux mixture, I buy it from the garden centre. I spray the entire plant liberally (stalks, fruit, flowers, on and under the leaves).
I think that you can spray at two week intervals.
hi all
ive just stumbled upon this site, its very helpfull. i too have been struck by tomatoe blight. ive been a bit neglectfull in the green house trying to juggle the world. i didnt even know tomatoes could get blite! i have 11 plats which were doing great yhen about two weeks ago i noticed the leaves were goig spotty and yellow. some of the fruits were going manky as well. i was going to use a bordeaux mix to try and save them. ive already taken away any sighns of blite last night. bless there hearts they look a bit like gauky teenagers now. im going make a homemade mix but im bit confused about how to go about it. i have copper sulphate and lime. but some people say to add soap flakes to make it stick a bit better. shall i ? also do i completely saturate the whole plant? also do i need to do it again?
sorry this is a bit a long post, so many questions
thanks in advance for any help
best wishe suzanne
Hi Sally
I’m out morning and evening inspecting my plants. Snipping any iffy leaves and following Kate’s (uk) advice – examining the stems. All is well ATM.
Finally the greenhouse toms are turning red!
Hi Kate (uk)
Thanks for the advice – much appreciated as always.
Hi Lincoln Lizzie
The thinning of the leaves would have given the plants a better chance against the blight. The prolonged wet weather produced the ideal conditions for blight to develop.
I grow some toms along the SW wall of our cottage. This year I moved the growbags away from the wall (about six inches) and also pricked the base of the bags for better drainage. In hot weather they need a drink morning and evening but seem much less susceptible to blight this year.
Hi Chloe
Thanks very much for this advice. I have pots of tomato plants standing on gravel in the greenhouse this year (rather than in saucers) and they have thrived.
Thanks for sharing.
Last year, i had my tomato plants in large pots inside a polytunnel on a concrete base. All tomatoes were fab and no blight. We subsequently had to move the polytunnel and we made it larger and put a polythene on the floor. Unfortunately the polythene does not drain any excess water away and so all my tomatoes have blight. Early next Spring, i have decided to put another concrete base down which is porous, so any excess water will evaporate and soak through the concrete – thought this might be useful to any of you with wet floors or damp conditions. regards chloe
Like many people, I am in mourning for my 9 tomato plants which were laden with fruit – blight got them and blitzed the lot within a few days. The blight didn’t hit until I’d thinned them out to let the light and air to the fruit. I’d grown them on a s.w. facing wall and wonder if I should have thinned them earlier? Was the pruning the opening the nasty spored needed to get a hold?
Thank you for giving me some more info and clues to look out for.
I read your comment and was straight out the back door for stem inspection. So far they look alright. I will keep watch.
Looked at your photos- the real giveaway is when black marks appear on the stems, but by then the fruits will probably be affected too, so watch the stems like a hawk. I would,if your fruits are of a good size, pick the trusses off the plants and ripen them indoors, they will ripen happily,or, if they are affected by blight they will get brown scabs on them as they ripen and you can discard the blighted fruits. Leaving them on the plants too long can result in all fruits being affected, taking them off smartly can save most of the crop.
There is no easy answer! It has taken me three years of blighted plants to become ruthless enough to act as soon as I see any sign of blight, discarding plants you have spent months growing, just as they fruit is distressing, but by acting fast you can save some of the crop.
Thank you for writing this post.
After last week’s heavy rain I too discovered it on about 6 or so of my 50 plants. But snipped off the affected branches and when it didn’t return sighed a sigh of relief. And then pretended nothing had happened !
However after last nights rain it’s back.
But having read your article in the meantime I went back out first thing this morning, found it and snip, snip, snipped ! I will keep a close eye on all my plants and hope as you say to keep it at bay for as long as possible.
Hi Shell
What a shame. There’s nothing like a fresh tomato plucked straight from the vine. But they are a real hands on vegetable/fruit and if struck down by blight have been tended for months already.
Good luck with the greenhouse. I love mine – it’s my sanctuary.
tried growing toms for the first time.Going well then something struck-what a shame Gardeners world didn’t feel able/bothered to explain what could happen to their- newly nutured seeds ! BLIGHT that is.Thanks for the info on your site-very helpful and informativeI’ll definitely pay you another visit.Hubby S teve currently building greenhouse.Hope to have more luck next year”