outdoor grow in norway, Indica

the plants are now about 3 months and 1 week old now, most of the bottom leafs are going yellow and
dying.. they are about 120cm. they will flower anytime now, the sun is 13/11 right now so soon it wil
be 12/12. the stems also havblack dots on so i can se they are sick and it is cold aswell.

might be a nitrogen deficiency.....is it only the bottom leaves......or the inner and older fan leaves? if it is just the bottom leaves(working its way up) then it might be N def