Tomato blight outdoors

[jc47]

My outdoor toms have had blight. I have removed all plants and fruit from the site.
Do any members have any suggestions on how to treat the soil apart from deep digging ?

[nickdub]

I would definitely not bother doing anything to the soil. In my experience outdoor tomatoes always get blight. it's just a question of when, and that seems to depend more on the weather,
My suggestion would be if you have time and energy to devote to doing something towards protecting the plants would be to find some sort of clear sheets like polycarb and to make some roof panels with which you can keep the plants drier in the Summer next year by building a frame round them.

[jc47]

Thank you for your suggestion. I have a parafinn flame weeder that I have considered using to try and destroy the spores that may affect other crops.

[NannyGreen]

Oh dear jc47 that is so disheartening, losing any crop is not good. I am not a 'proper' gardener but thought I should share my own experience.

About 5 or 6 years ago I had blighted tomatoes outdoors (I always grow a couple in the greenhouse and a few outdoors), I destroyed all offending material and replaced the soil around and to a depth of about 10". Following year more blight so I swapped the herb area for the tomatoes - upset my neighbour who was used to leaning over and picking a few, now out of reach!

That was 3 years ago, herbs all doing well and very good crops from all outside tomatoes since, also had to relocate potatoes which are also doing well. I do hope you find a solution that works for you

[Mr Bones]

Late blight can only survive on living plant material so there's no need to do anything to the soil. Affected plants can be composted as long as they do die but it's advisable to cover them to prevent spores being carried by the wind.

[ameno]

As said above, late blight can only survive on living plant material, and what's more the spores themselves cannot survive long without a host (maybe one month, at most), so there is no risk of passing it on year to year.
It is good practice to contain the contaminate plants to prevent the spores spreading, but that is only to prevent infection of plants (yours or other people's) in the here and now.

Late blight usually survives over winter on infected potato tubers, which then start growing again next year, succumb to blight early, then spread it to other plants.

I would definitely not bother doing anything to the soil. In my experience outdoor tomatoes always get blight. it's just a question of when, and that seems to depend more on the weather,

When do you find yours usually get blight?
My main crop potatoes start showing the first signs of late blight two weeks ago, so I cut them down and disposed of the haulms, but the tomatoes, despite growing close by, are still completely unaffected.
Admittedly, six of them are Mountain Magic F2 (seeds I saved from Mountain magic last year. Only one of the six actually looks like Mountain Magic, though. Most seem to have turned into small plum tomatoes), but I don't know how much blight resistance they will have actually inherited. And the other three are just random varieties that sprung up in my garden compost, presumably from discarded shop bought tomatoes, and seemed to be growing strongly so I kept them.
It's been pretty warm, humid and damp here lately, too, perfect for blight, yet still nothing.

[jc47]

Thank you all for the benefit of your experience. The 24 plants affected were plum tomatoes
12 Roma VF and 12 San Mazarno VF . I had a similar problem 3 years ago , it is perhps
the result of growing too large a crop .

[nickdub]

I don't grow potatoes these days so can't comment on that - as for tomatoes it's unusual for me to have any outside but as I couldn't get rid of all my spare plants this year I planted about 10 outside in odd spare patches of the garden, so they are a fair distance from one another. Of these the marmande got blight about 10 days ago, so I disposed of those, 3 other varieties still unaffected touch wood.

[bikermike]

I have had blight this year, it's been hot and damp, so it's a big year for it.

I have looked at various sites, the general opinions split into "kill and burn everything" and "it's only on living material, so your safe".

The only one with a bit more of a nuanced approach was "are you sure that the composting is complete" I am chucking away the very blighted stuff (as I don't have a hot compost heap), but relying on composting /breaking down for the less-blighted stuff.

There was also a worrying article that suggested that blight my have acquired the ability to generate spores than can survive without living material. I can't find the flipping link now.

How do Americans deal with blight? (seeing as it's endemic there AIUI)

[ameno]

It shouldn't matter whether the composting is complete or not. It can't survive without living material for very long (the potential of those new spores you mention notwithstanding), and there is no way an uprooted tomato plant will still be even slightly living come the spring.
"Burn it all!" is the standard knee-jerk response to any diseased plants, but the fact is it's often no necessary. It's the usual recommendation for powdery mildew, too, but that also can't survive long without a living host, so is similarly perfectly safe to compost, even on a cold heap.

[ESBkevin]

Tomato blight outdoors is a fact of life on our allotments. We got the potatos in early and watered well during that long hot spell when we normally get rain. We lifted them as soon as the first earlies were done and the hulms became less plump. Better a clean crop than a big crop covered in slug damage or blight.
We have enough tomatos in a small 6x8 greenhouse to serve us usually, so all the remaining plants go up the plot outdoors. We expect to get a surfit until about the end of August to fill the freezer or make sauces etc. and then get them into the compost, the plants were stopped at the end of June this year and will be out as soon as blight shows up now.
Active compost will get rid of any blight on the plants.

[ameno]

Well, my two volunteer tomato plants have succumbed quite badly to blight in just the last few days.

My Mountain Magic F2 plants, however, are still showing no signs, so clearly they've inherited a reasonable amount of resistance, despite the fact that none of them look like their parent.
I've decided to save some seeds from the best plant (plum shaped tomatoes, large cherry/small salad size, very tasty, good yield).

[MarkPelican]

Hi Ameno,

Are your Mountain Magic F2s Regular or Potato Leafed? I've got one of each, the potato leafed seems a better fruit, earlier and stronger. The regular leafed seem to have infected the rest of my tomatoes with bacterial canker / wilt. (Mind you the seeds I saved from the allotment came from plants that had got blight so I suppose I should have suspected something would be bad about them).

[ameno]

Hi Ameno,

Are your Mountain Magic F2s Regular or Potato Leafed? I've got one of each, the potato leafed seems a better fruit, earlier and stronger. The regular leafed seem to have infected the rest of my tomatoes with bacterial canker / wilt. (Mind you the seeds I saved from the allotment came from plants that had got blight so I suppose I should have suspected something would be bad about them).

All regular leaved, and all seem to be resisting blight well, although the fruit are quite variable.

Only one looks like the original Mountain Magic (a small, round salad tomato).
One produces larger, slightly lobed fruit, like a small beefsteak tomato.
One produces strange heart-shaped fruit which seem to take ages to ripen and are very prone to cracking. Bland taste, too.
One produces cherry plum tomatoes, also prone to cracking.
And two produce small salad-sized plum tomatoes (about an inch wide by an inch and a half long). These ones are the tastiest, the best cropping, and seem resistant to cracking, so I've saved seeds from these.

All these came from seeds collected not only from the same plant, but the same fruit. They really are highly variable.

[jdlondon]

I'm getting confused by whether it is late blight or leaf spot or canker etc - black spots and stems is what's showing on mine, all outdoors as I don't have an indoor set-up.

I've been spraying baking soda and neem oil etc, but it's been rain on and off, cold then hot, that I'm pretty much throwing my hands in the air in despair.

You say get rid of all the plants - does that mean the fruit is inedible? Can you get sick from eating them? Most of my fruit are green and a couple have black colouring entering it - but I thought it was because it was the black variety! I had so many plants from so many sources I lost track of what was what.

I put the pruned leaves on the manure/compost pile, but then read up and plonked the last ones in the burner bin and worried about the ones deep in the compost - but I'm reassured by the living tissue requirement some of you have mentioned. Thanks.