Celery, Par-cel, Celery leaf and Celeriac

I've grown them all at one time or another as I love the celery taste.

I've grown normal celery (plagued with slugs) self blanching (tuff as auld boots) celariac (no bigger than tennis ball) and leaf celery.

I only grow leaf celery now (Kint sai) or its deriatives. A couple of leaves in a soup or stew gives me the desired taste. I have tried to perennialise it by chopping it right back. Some leaf celeries are supposed to be perennial but I have struggled to keep them going a second year.