Don't give up on very leggy tomato seedlings
My favorite tomatoes (Rosada) come in a packet of 6 seeds. I sowed them one weekend in a heated propagator and went away for a few days. Five days later they were through and so so leggy. They were falling over. I dispaired that they wouldn't recover and as time went on I was about to give up on these leggy specimens.
I decided to try a drastic move... nothing to lose. I chopped them off at about two inch length and replanted them in compost. E voila! They have produced really strong seedlings and now sturdy plants. They are now in their final pots and producing trusses.
I tried this last year with a withering cucumber and that was successful too.
Takes a bit of nerve but worth a try. Saved buying another packet of seeds at £3.99 for 6 seeds.
Hope this helps someone who is about to give up!