For hydrangea pruning questions, you might check out
http://www.aldridgegardens.com/askeddie.htm. This is the aldridge gardens website, and Eddie Aldridge is well known as a hydrangea expert. From what
I understand, he was instrumental in finding/propoagating the "snowflake"
oakleaf hydrangea cultivar. He answers pruning questions, depending on the
species.

I have never removed old mulch. by the time fall comes around and I start
dividing or cutting back stuff, the old stuff gets mixed around and sort of dissapears anyway.

Michelle,

I don't remove old mulch either - i just add to it. My plants are fine, so it must be working!

I don't know that i would cut back the lantana at this point, but perhaps in the spring. I have HEARD (from where I don't remember) that cutting them back can cause problems during the winter - however, others do so and have no problems. I wait until the spring to cut mine back, around the time it starts putting out new growth.

Rosemary

Wait until Spring to cut back lantana. The stims are hollow and water can get into them and freeze(killing the plant).

Tony

I say "DITTO" on tha Lantana, leave until Spring. As far as the Hydrangeas, you have to know 'how' to cut it back if you want it to bloom. If not pruned properly you may cut off this years growth & next years blooms. I just let mine go except for removing the old flower heads. As far as mulch, also just leave & add to. Betty

Last year I didn't prune my lantana in autumn. I did mulch with leaves around the main stem. In years past, I have pruned it and covered the stems with a flower pot full of leaves. My lantana did the poorest it ever has this year. It was slow to sprout out and slow to grow despite plenty of rain. I'll definitely prune after frost and cover with pots of leaves this year.