Maybe just a bit of transplant shock. Especially if you immediately put them in the GH, direct sun, if it was hot in the greenhouse, etc. Transplanting can be a bit of a shock at times. As long as they bounce back they will be fine. Just avoid feeding or over-watering until they get re-adjusted.

Any of the balanced liquid ferts with micros works fine just use it diluted to half strength or less.

Dave

I think of two reasons:

1- You did not plant them deep enough.
2- You did not pack the soil around them real good when transplanig.

But then, if trasplants are tiny, you have to water them gently.

Thanks for the replies l just wanted to note that they were grown indoors under flourecent light and as far as depth I planted them up to their seedling leaves. Maybe they were too weak or I shouldn't have wet their leaves.

Did you Harden Them Off?

If not, it is urgent that you shade them immediately until they've acclimated to being outside.

Yes they have been hardened off they have been in the green house for about two weeks now. I watered them again yesterday and most stayed up only two or three fell over but as of this morning are back up again.

Mine seemed to do the same thing. I gave them filtered water until they grew a little larger and started to bloom. For some reason the plants did not droop when I did this or when it rained.

This is a common problem with freshly potted up tomatoes/or even freshly planted tomatoes in the greenhouse.

Usually because the main stems are too juicy and weak at that point,when you water them the water collects on the top of the leaves and weighs down the plants to the ground with the water droplets that do not run off the leaves straight away.

You can get over this by -either shaking each individual plant slightly to remove the water droplets weighing them down,or you can get a watering can with a small fine spout on it and carefully only water them at the roots compost surface without letting it get on the leaves.

Usually it occurs most in plants that have become a bit leggy and taller than they should be.

After a while as the stems harden and become more woody the problem will cease.

Just ad a fistful of soil aroun the stems and press down gently.
If they have 2 or more sets oftrue leaves, pinch off the seed leaves and pack soil up to under the first pair of true leaves.

The same thing just happened to me, only 1 min after watering my tomato plant they all flopped over. I think I got water on the leaves while watering them? I posted a stick next to them to help support them, I'll also check on them more regularly?

Any ideas, beside what I've mentioned and maybe removing some lower shoots and packing them in more soil?

Have I over watered or over fed?