I have a large celery fern that I moved indoors for the winter. It is not doing well and is making a mess. It is in an 18″ pot and has a 3 ft spread. I have limited places to keep it since my cats started eating it. Can it be severely pruned and overwintered in a cold location?
Your plant is also known as an Asparagus fern, (Asparagus densiflorus Sprengeri Group) and in fact is not a fern. You may already know that both leaves and berries of this plant are toxic to cats and other animals as are many other members of this plant family. Please see the links below for information on toxicity.
Moving houseplants indoors after a summer spent outside often causes stress in the form of dropping leaves and dieback as plants adjust to different light and irrigation levels. You can certainly prune your Asparagus fern back, getting rid of the dying, yellowed branches altogether by cutting them back to their base, and pruning the remaining branches for a more manageable shape. The Asparagus fern does not tolerate freezing temperatures but should respond well in a cooler environment. Our dry homes in winter are not ideal, and although these plants are reasonably tolerant of dry conditions, you might mist the foliage to provide humidity if your conditions are particularly dry. Asparagus ferns do not mind being root bound, so repotting should not be necessary. Some general guidelines for care are available here: , and information on toxicity is outlined in these websites: