These often develop bare sections, you might try cutting back down low in spring to get a new top coming along. Otherwise a warm and sunny position with good drainage is preferred.

no plant holds its leaves forever ...

the oldest leaves are interior.. and are usually shed in fall .... and can be increased by various stressors ... drought.. high heat... too much water ... etc ...

without a pic.. its impossible to tell if yours has a problem.. or this is normal ....

if it flushes out with normal vigor in the spring ... then i would presume there is nothing wrong with it .... and pruning it.. would have been for naught ...

if it does not ... THEN is when i would worry about it ....

leaf fall in fall .... isnt really a time i worry about.. well... leaves falling.. even on evergreens ... as long as its primarily.. interior ...

either show us the plant.. or ignore it until next year .... [and even if you show me.. i will still probably tell you to ignore it]....

and no ... personally.. i do not believe in fertilizing a stressed plant... its stressed... not hungry ... and only grandma.. thinks food heals all.. lol ...

ken

ps: leaves are the food making machines of a plant .. and if yours is stressed.. and you go cutting off all its buds for next year.. how in the world are you helping it .... in my logic.. fuzzy as it is... you are only setting up a new stress.. for next year ....