Sorry for baring bad news, but the tomato blight has arrived on the allotments, so if you haven’t already, I guess it’s probably best to start spraying.
Don’t do what I did.
Not one for throwing things away, last Sunday I thought I’d check the remaineder of some Dithane that I had mixed up in a bottle in the shed from last year. After shaking the bottle the appearance seemed the same as I remembered it to be, in that milky, yellow, cloudy sort of way. So ignoring the instructions on the packet, (i.e. to use it straight away and not to store the mix) and promptly sprayed my crop (about 50-60 plants). One week later when I visited the plot today, blight had caught hold of most of my toms. I’ve removed all the infected parts, plucked a couple of hundred of green and brown toms and ripped up those plants that were worst hit.
I guess part of me cynically believed that the company who makes this stuff didn’t want you to save any from one year to the next as it would affect their sales. Big mistake. Now to mix up some fresh brew.