tomato leaves turning white,help please

[matowakan]

I have grown my tomatoes in the polytunnel after starting them on a windowsill in the house.
They are about 6 -8 inches tall.
I noticed today that they are all starting to get white spots on the leaves.
I cannot find out in any of my books what this is.
They are in a border so they are not pot bound.
The pollytunnel is unheated.
Can anyone please give me any advice as to whether I need to take them out and start again or whether they will be ok.
Everything else in there is ok and growing well.

[Green Aura]

I don't really know what the problem is but one idea is - if it getss really hot in the polytunnel in the sun (ours has been getting to 50oC during the day) and you're getting water on the leaves it may be scorching them. Try watering them just round the roots and see if it stops.

If it's just a few leaves and the rest of the plant is OK I'd take them off just in case (of what I'm not sure).

The other thing is it might be some sort of mineral deficiency in the soil - a quick drink of comfrey, seaweed, nettle or horsetail tea (or a mixture) might perk them up a bit - or if you use fertiliser then just a weak application of an all-purpose type, not tomato feed it's too early yet.

Unless the plants generally look unwell I'd leave them be for the time being, unless you see it spreading or moving on to other plants.

[matowakan]

Thanks for that-I fed them about 10 days ago with a general feed but a weak mix,it does get hot in there even when opened up,quite often it can be about 25 - 30 at midday.
We will see what happens!

[Annpan]

I don't really know what the problem is but one idea is - if it getss really hot in the polytunnel in the sun (ours has been getting to 50oC during the day)

YOWZER!!!!!

[Green Aura]

Oh yes - we've got a min/max thermometer 4 min/50 max. Hastily working out irrigation system.

[Millymollymandy]

That's why when I did have a greenhouse it didn't get used after mid May! I couldn't go in there, let alone any poor plants!