Help! Save my Tomatoes!

Some of my tomato plants have died, with others the leaves are going white and dry at the ends - are they short of some nutrient?

I grew them from seed with these all in one compost plugs then planted them up in specialsed compost for bringing on veg and have brought them in every night for the last two weeks whilst I acclimatise them. 

Am new to this so any suggestions gratefully received!

If your going to grow these outside, its far to cold. June would be a better month. IMO, a greenhouse is the only place for tomato plants. Have you been potting these on ?? What size pot are they in ???

They do indeed sound rather chlled to me, if there is still signs of life, keep them warm and covered for another few weeks, and try again.  Until the last couple of days it has been too cold for tomatoes outdoors - think about where they evolved>  It doesn't get very cold in Peru!!   You potted them into 3 inch pots after pricking out I guess, what then?  They could be in 6 inch pots now, then in a couple of weeks if they are getting to fill those with roots, you could think about putting into a grow bag, pot or however you want to grow them.  Over potting or putting into a grow bag while they are too small will kill them too, as they cannot use the compost and it gets cold around their baby roots.    Hope they do for you, just be patient. 

Thanks guys I think you'v both hit the nail on the head as i wondered whether it was from putting them out on a windy (cold) day! I'll keep them extra warm for now before trying them outside again! And appreciate the advice about potting on too - thanks again