It all depends on the variety of coral bells you have and how fast they grow. I've had 'Vermillion',a very slow growing one, in the same spot for about 5 years now. I just 'freshen' the soil by adding compost each year. Most of mine are still in the same spot and have been for 4-5 years. I also have one called Frosted Mint? (can't remember exactly) and it has been in the same spot for 7 years and only now needed dividing. The way I look at it, see how fast it grows and if it gets to big, divide. I always divide anything in the spring. Doing it then gives them lots of time to get used being divided and set roots before fall. Marg

Hi,
A lot of plants will start to die out in the center over the years, they send out runners,babies, rhizomes and the parent eventually dies off. You will be able to see when you need to get out the center. Dig it up cut out the dead stuff and replant the healthy newer growth. There is no hard fast rule for timelines it is more as needed in my experience.

I agree with squirelette. I have had coralballs in the center of my planting boxes for 5 years. I have hesitated to divide them because they put on a terrific show every year and this year will bw no exception. However this year I noticed that the leaf base has humped up to about 12 inches instead of laying flat on the ground, so next spring I intend to divide them. I think this is the way the plant is telling me it needs dividing.

Others plants than coral bells will die in the center but I don't think coral bells will. Still others will just get to be too big and that's the time to divide them--like my stella d'oro lily.

Just use your common sense when dividing perennials, if you think they need it then it probably does.

Sometimes it's a case of adding more soil over their emerging stalks to allow more fullnes. I have had to tidy up 'purple palce' in the past.

I read the same thing in another garden guide. Basically it's a way to propagate new plants. It's not absolutely necessary but it's a way to keep things tight and low to the ground. You could take off the tips and from that create new plants easily(I heard).

ianna