Black Veins on Tomato Leaves?

r.a.i.n.b.o.w

My friend had black veins on his tomato leaves and said it was blight - I've seen pics of blight and didn't think it looked like it as it attacks the tomatoes too, and his toms were fine. But he's a more experiences gardener than me, so I took his word for it.

Today in someone else's garden (one that I'm going to be using to grow) I saw a tomato plant with exactly the same - black veins on yellowish leaves, but perfectly fine (although unripe) tomatoes.

Any idea what black veins on yellowing tomato leaves is?

wssla00

I sometimes have purply parts of my leaves if they have got too cold- could be that? Or that they don't have enough feed?

Lotus-eater

Yellow tomato leaves usually just means the leaves are getting old and are useless to the plant, so they die and drop off.
But whatever it is, it certainly isn't blight.

r.a.i.n.b.o.w

It MIGHT be the cold, but this black vein thing affects ALL the plant (although not ALL the tomato plants in the garden) just not the fruit. I did think it might be underfeeding.

Lotus-eater - the leaves aren't yellow like a dying/old leaf, these are yellowy with black veins, 'healthy' albeit not green?

I'll have to get a pic, hopefully next week.