I had a bunch of bag seed in a pot near a window once that did the same thing (though mine was more overgrown). what I did was pull the sedling up out of the ground trying to keep some root from breaking off. then tossed them into a bubble tub. I let the long weak stems go down into the water and set the leaves even with the lid (to remove stretch). the stems ended up growing roots all along it and after plants got "right" i moved them back to dirt..I was just goofing around but it worked well enough.