Hello Adam,

I have margharite daises in my garden - three kinds: yellow, pink and white.
I've found that the leaves at the bottom of the stem do wither and turn
brown. That's ok - the stem or canes are just growing old.

What you need to do is to prune the plant heavily in late Winter. Then when
Spring comes, the plant will come up with new shoots. Don't prune the plant
in spring or summer if your seasons are very hot. In Summer where I live, I
pruned some of my daises in late spring but before the new shoots could
establish themselves, they were scorched by the summer sun and the plant
died.

If you don't do this, the plant will have a small patch of leaves at the end
of all the stems.