Pruning Santolina Overwintering Under Lights

This is Linda Rankin again, asking about my Santolina again. I did as you suggested and transplanted them into pots in September and have had them under lights 16 hours per day since. They are doing marvelously, growing up and out – a lovely grey/green. But they are now growing amongst the lights themselves and I can't raise the lights any higher. My question is – is it safe to prune them as if it were June and they were in the ground? And in pruning them, is it possible to just take a horizontal cut off the top, as if I were making a hedge? The intent of the santolina is to form a low hedge along the rose garden walk.

Yes, you can prune your plants back and keep the foliage below the lights. And yes, you can simply shave them as you would a hedge.