Tomato Doctor needed for diagnosis

[OllieMartin]

My tomatoes are looking a little worse for wear, I've salvaged one in an attempt to diagnose their ailment.
According to my gardening book it's either a magnesium deficiency or verticillium wilt, but wondered what you experts thought:



The leaves have wilted and have gone pale yellowish beige in patches. Some of the smaller plants have bent over.
They're kept in a plastic green house, which I have been keeping open lately to harden off some of the other plants in there. They are quite well watered.

I'm thinking either:
- Keeping the greenhouse closed
- Stopping watering
- Applying a fertiliser (I just recently applied some nettle tea)
- Spraying with Epsom salts or magnesium foliar spray

Thanks for any tips

[teakdesk]

Ollie, I think you are worrying unnecessarily.

The picture looks pretty healthy to me!!!


The patches you mention are probably just sun scorch due to droplets of water getting onto the leaves.

The leaflets do not look yellow to me - when books say yellow they mean really yellow.


I'm thinking either:
- Keeping the greenhouse closed - not during the day or they'll get too hot.
- Stopping watering - yes, they need to be dry-ish until the fruit comes.
- Applying a fertiliser (I just recently applied some nettle tea) - not needed but a little general or nitrogenous feed (not tomato feed until you can see tomatoes) could be given.
- Spraying with Epsom salts or magnesium foliar spray - do not spray the leaves. Water a little epsom salts on the soil if you really want to.


Good luck.

[OllieMartin]

Cheers for the advice.
This is only a smaller plant, the larger ones are much yellower, also my fantastic camera phone likes to brighten things up, especially with the flash, so it's hard to make out the yellow.

Will take your advice and see how they get on.
Many thanks

[teakdesk]

With respect to the larger plants, if it is the bottom leaves that are going yellow then this is normal and not too worrying either.

On a large plant that is growing well but doesn't have enough light to manufacture chlorophyll in its new leaves it will transfer chlorophyll from the lower leaves to the new ones at the top.

Chlorophyll is what makes the leaves green so these lower leaves go yellow.

I just wait until the first flowers are set and then cut these yellow leaves off.



If it is the top leaves going yellow then that is a different matter !!

[OllieMartin]

Here's a picture of the whole crop:


As you can see, it's some of the top leaves that have yellowed

[teakdesk]

Hummm.... that looks a lot worse than I was imagining.

You'll get various answers from people here but to me it looks like frost damage.

Purple stems with dry, brown leaves (they look more brown than yellow on my screen) I associate with cold and wind - both of which my garden has had recently..

The cold damage would be made worse if they had been then left in bright sun behind plastic.

Personally I'd consider binning most of them as I think new garden centre plants will grow quicker than these could recover. Some of them may be Ok but it is difficult to tell from the photo.



I doubt it is disease - I go by the maxim "If you are on the High Street and you hear hooves behind you, it is better to think of horses than zebras!!" - we've had cold and wind followed by strong sun so that to be is likely.



But wait for some more replies before throwing them away.

Sorry, feel for you

[OllieMartin]

Thanks for the advice, as my first ever attempt at tomatoes, it's all new and I never know if i'm making them too hot, too cold, too wet or too dry.

If at all possible I'd prefer to salvage what I can as I'm on a tight budget.

So would you suggest not re-watering them (as they seem pretty moist) and leaving the greenhouse open during the day and closed at night?

[teakdesk]

Looking at the photo again there could well be some plants that will survive.

If you want to try and rescue them, then try a weak feed of tomorite (it's a bit earlier than normal but they could do with the potash). You could try a weak epsom salts as well if you have it.

Keep them warm at night and well ventilated and out of direct sun during the day. could you bring some of the smaller ones in overnight ?

Don't water for a while but do not let the compost get completely dry.

Remove the brown leaves.

[zazen999]

Personally.....I think it is the peat pots. They have run out of goodness and are drying out too much then not getting wet enough when watered....

I'd:
nip off every yellow/brown leaf.
repot as deep as you can into plastic pots or straight into their final positions. Leave just 1 or 2 leaves above the soil if you can find pots deep enough - or at least sink them down a few inches deeper than they are
give them a seaweed feed once a week until they set fruit, and then tomato feed.
never water from above, always water by putting into a saucer or try and filling that up - any left after half an hour tip it out.

[SarzWix]

I think it's a combination of the above - I have a few tomato plants still in 3" pots, the rest are in 5" with fresh compost. They all got quite badly overheated last week but the ones in bigger pots have recovered pretty well, while the ones still in 3" pots look as sickly as your worst ones.
I'd try the repotting thing, and keep them out of full sun for a little while if you can. (chuck a net curtain over your greenhouse if you can't move it/them)

[Flummery]

Looks like the leaves have had water splash and sun scorch too. Water from below - or at least from below the leaves - and not too much!

[Geordie]

As this post seems to contain advice about tomatoes and watering I just thought you might allow me to veer off on a tangent around this topic.

The first taste of a homegrown tomatoe is one of the absolute joys of growing your own. However there is just a possibility that you may find they arn't as tasty as you had hoped. If (fingers crossed) we have a hot dry summer that does wonders for sweetening your tomatoes can also be the cause of very bland tasting fruit. This is generally the result of an unblanaced sugar / acid ratio. For a perfect tasting tomato you need high levels of both sugars and acid to be present.

The reason we feed tomatoes with a high potash food is the amount of potash is directly related to the acidity of your tomatoe. But as this tends to be a weekly feed, hot weather often means you watering daily. This will wash out much of the soluable nutrients leaving a weak soil solution. Try using a half diluted liquid feed every time you water rather than leaving it for once a week. Its difficult to offer specific advice as there are many ways or methods of growing tomatoes.

So its all about the balance, whether you use soluable feeds or a top dressing don't water too much. In my opinion tomatoes do best for flavour if kept on the moist side of dry....very difficult if you are growing 3 plants in a single grow bag!

[OllieMartin]

Ok, I've brought 1/3 of them inside, 1/3 of them I'll plant out tomorrow and 1/3 of them I'll keep in the green house.

I remember reading about not watering from above, but don't remember being too strict about it, so that certainly sounds like a plausible cause.

Will certainly take all the above advice and let you know how I get on

Many thanks

[Alice]

Geordie - thank you for that Invaluable as ever.

Ollie, your tomatoes look sick.

I would agree with Zazen and say those little peat pots are doing them no good. Nothing did well in them for me and I will never use them again.

I would have the tomatoes out, strip off all the rubbish foliage , plant them as deep as you can in plastic pots and keep my fingers crossed.

Tomatoes are tough cookies. Hopefully they will come good. Good luck.

[OllieMartin]

Well I've taken to removing them from the greenhouse during the day, and whilst I wouldn't say they've 'bounced back', they certainly haven't died any more.

I think I may have a tomato crop yet.

In other news: You can get some pretty decent, established tomato plants in Wilko's for 75p