What kind of large fuzzy plant is growing in my nw us garden?

I have a few large plants growing in my garden, that have grown to about 2 feet high and approx. 3-4 ft wide. They have broad, very fuzzy leaves. The fuzzy, furry coating gives it a somewhat silvery look. The stock is very thick. They are difficult to chop or dig up. When I did chop some off just above the soil level, the leaves very quickly turned brown and became shriveled. I live in the Pacific Northwestern USA. I have tried looking it up, but must not be looking in the right place. Can anyone tell me what these plants are? Thanks!