yellow veins on tomato leaves

lora

My neighbour has this problem. Otherwise plants seem healthy. Is this a virus ?

foxgloves

It can often be a nutritional deficiency, though last year, I got funny colouring on my tomato leaves just from the cold temperatures.

Budget_Gardener

The one to look out for is tomato blight, and that's easily found on a Google search. It's a yellowing and brown spots too - irregular watering can cause that. Yellow veins don't sound too serious; if you reckon it's blight then remove and destroy any parts that look affected.
I also had problems with temperature discoloration last year; I don't think it was blight and this year's selection are similar, or at least the ones I've bought in rather than grown from seed.

Badrick

They can look as described through a lack of magnesium, which is treated by spraying with Epsom Salts. Dissolve ½ oz in a pint of water.and spray each day for a week (best done in evenings, as plants may scorch in direct sunlight).

Miss_Havisham

i agree with the epsom salts solution.

Once they improve, feed them regularly with any tomato food (I use Wilko's own make for a couple of quid, no need to buy an expensive brand).

Once the tomatoes appear they will need regular and consistent watering. Don't leave them to dry out in betweeen watering as this can cause the toms to split their skins.

Miss H