Raising Existing Beds

Raising Existing Beds

Hello all. I have a question. I have some established hosta beds (there are tulip bulbs, ferns and hellebore in there as well), they are specimen gardens and I would like to raise them, they are currently very, very flat and not the best for viewing. Is there a way to raise the beds even though they are planted without killing wha tis currently planted in there? I don't want to build walls I'd just like a gently sloping hill so the plants appear more separated as they are fairly crowded at this time and getting difficult to view My idea was that in the fall after everything has died back to add dirt or compost to the beds to create "mounds" and eventually rearrange the plants so the taller species and larger species are in the back and the smaller ones are in the front for a better aesthetic. My fear is that if I mound up dirt/compost - what have you that it will be to deep in the back for the plant to come through in the spring and I will have killed them. Here are some not so great pictures of what they look like today (the last one is kind of blurry the dog bumped me!) Ideas, suggestions???
Early Gerbera Blooms

Early Gerbera Blooms

newbie here, i come with a question.

newbie here, i come with a question.

so ! i finally cleared my room – more or less.

so ! i finally cleared my room – more or less.

Ikea Couches

Ikea Couches

From my daffodil bed…

From my daffodil bed…

Free standing SUPERSIZE bathouse

Free standing SUPERSIZE bathouse