Damaged Onion leaves

I signed up to GYO couple months ago and got the free 90 plug plants that came with it about 3 weeks ago, including 10 onions.

Now I squished those 90 plants together pretty tight (I'm a total newbie to veg etc and didn't realise the spacing needed!) untill I could buy more pots/planters and compost to space them out better. Which I done a week ago.

Now the main reason we didn't have a veg patch yet was because we had two huge conifer trees in our garden (bought house last september) and several large tree stumps and roots.

Anyway we finally got the trees chopped down yesterday and the tree stumps ground down so will hopefully have a nice veg patch next year. however the people must of chopped the tree down with one of the branches landing on a few of my planters, completely snapping all but one of my onion leafs, one very badly, like down to 1cm above ground.

Will these surivive and grow back? and If so what can I do to help them? Feed more regularly?? The feed I've got is high Nitrogen (brand = MG) but obviously being brand new fresh compost I've not fed yet. (been feeding before when squished as I assumed nutrients would be getting depleted quickly).

Thanks in advance,
Ryan