To identify them we need close ups of the foliage of each one.

With conifers, which these are, brown = dead so there is nothing you can do to save the one which is entirely brown. The brown parts on the others are also unsaveable. Trimming or fertilising will definitely not help.

You can't fix that. It can only grow out of it. The damage looks so severe that could take a very long time or never happen at all.

and conifers are trees.. and grow in tree time .. if you cut away all the dead brown stuff.. it might be 3 to 5 to 10 years for them to recover ...

imo.. remove it.. and move on ...

ken

ps: imo .. and i had a collection of hundreds of trees and shrubs.. and i NEVER fert'd them in my sand... unless potted long term.. just forget about fert'ing such ...

never heard of the garden restoration forum.. go figure on that ...

anyway.. my first house.. i wanted to maintain the garden of the house as history ... 5 years later.. and many nightmares later.. i finally got rid of the last mistake the prior owners made.. and good riddance on that ...

you should also get rid of old problems.. and not waste time trying to 'save' them ..

ken