[barbarella]

Help - last Friday we moved our 3 growbags of  tomatoes into our new greenhouse and I was just removing the lower leaves on the plants when I splotted what looks like blight on one of the plants.  I have found a website which says that outdoor plants already infected will get worse when you move them inside because of the humidity.  I have photographed one of the leaves - can anyone definitely identify it as blight?  If so, I will move the growbag back outside as soon as it stops raining (sigh!).  All the other plants look healthy and this particular growbag was in a different part of the garden before so is there a reasonable chance they will be okay?

[gillie]

I think that is blight.

I would immediately spray all the plants very thoroughly with dithane.  There is a good chance that will save them, but you  must do it straight away.

Gillie

[barbarella]

Thanks Gillie, I'm off to Homebase right now 

[gillie]

There will be too much dithane in a sachet for a few tomato plants.  I use one quarter of a sachet at a time.

Gillie

[barbarella]

There are nine plants in growbags and several more in pots.

[barbarella]

Homebase no longer stock Dithane but I managed to get some in a local shop.  It's not going to easy measuring out a quarter of a sachet, but as you say I won't need 2.25 litres of the spray.  I could also spray the roses as some of them are showing signs of blackspot, but at the moment it is tipping with rain with no sign of a let-up.  The packet says use immediately - does 'within 24 hours' count as immediate I wonder?

[gillie]

I tip the contents of a sachet onto a sheet of paper, scrape the powder into a heap and then 'cut' the heap into quarters using an old knife.  I push the contents into the four corners of the sheet of paper, then cut the sheet into four and fold up three of the little heaps into neat packets to use later.

I understand that drug dealers 'cut' drugs in a similar method.  However I learned to do it packing wild flower seeds from a botanical expedition.

I use Dithane as soon as I have mixed it up.

Cheers,

Gillie

[barbarella]

Thanks so much Gillie - that is really helpful to me, and I am sure lots of others

[barbarella]

I have just been out to spray them and I have found a few more plants affected including the ones still outdoors, so I don't think moving them indoors has made any difference as they must have already been affected.  Like Wellingtons' post (Blight in the Greenhouse) I will have another look at them tomorrow and remove most of the foliage and hope for the best.  There is lots of good sized fruit but all green - I wonder if I cut some trusses now would they ripen indoors? 

I lost my tomatoes to blight last year but thought it was just bad luck and the weather was great this year until July. I have grown tomatoes outdoors in the past with no problem until last year.  Maybe it would be more sensible to spray in future years at the first sign of damp weather.  Is that what most people do?

[Lee G]

I have about 50 tomato plants down the plot and nearly all seem really badly affected, not sure when I can get any Dithane as I'm working during the day.  Gutted. 

[barbarella]

Dithane doesn't cure blight, it only stops it spreading so it won't be much good once it has got a hold.  I removed a lot of the leaves from my plants today - not sure if that will kill them anyway but what can you do

I noticed some people in other posts managed to get Dithane for about £4 for six sachets.  I paid £8.25 in the local shop - crooks!  Then I found it online from Wilkinsons at £3.99!  Actually I just searched it on Amazon and found you can still get Bordeaux Mixture by Vitax from a company called Heritage Home and Garden for £3.75.  I thought this was no longer available - does anyone know about this?

I have just registered on a website called www.blightwatch.co.uk where you can see if it is in your area (bit late for us  ) .  Apparently it is all about Smith periods when the temperature and humidity are above a certain level.  It might be too late this year but next year I am going to keep an eye on weather conditions and spray as a precaution. 

I don't think I will bother spraying my potatoes though as there are too many.  I will just use blight resistant varieties and if they get affected, just cut off the haulms and leave it for a week or so before lifting the spuds. 

[gillie]

Bordeaux Mixture is being phased out and will become illegal within the EU within a few years.  I suspect it is more harmful to the environment than Dithane and  possibly less effective.

I have registered for Blightwatch too, but you have to remember that the microclimate within a greenhouse will be more 'Smithy' than in a potato field.  I know 'the books' say that blight is rare in greenhouses, but I don't know where the evidence for that comes from.

I lost all my tomatoes to blight a few years back.  Now I spray!

Gillie

[barbarella]

you have to remember that the microclimate within a greenhouse will be more 'Smithy' than in a potato field.  I know 'the books' say that blight is rare in greenhouses, but I don't know where the evidence for that comes from.

Yes, I agree.  You have a catch 22 situation with a greenhouse.  If you keep doors closed the humudity will increase (and the temp will go sky high) but if you open them the spores will get in anyway!

[penance]

I'd save the money and not use Dithane.
Dithane is a preventative, once blight is on the plant the only real thing to do is get rid.

You may get away with removing infected foliage but Dithane wont stop it spreading on the plant.

[chimaera]

Are some varieties worse at getting blight than others?
A few days ago all my outdoor Roma toms went down, I removed them and the other vareties in the same row seemed OK. I sprayed these with bordeaux and other than the odd leaf, they seem (so far) to be resisting. A plot nearby has also lost all their plum toms, but others growing other varieties seem so far to have escaped.
Charlie