I have a knockout rose that I have had for several years. It's blooming and getting new leaves on top but the bottom is bare - no leaves. I live in North FL and the weather has been hot. This year we added rubber mulch to our flower bed. My other rose bush is not bare on the bottom. What can cause this?
It looks like you have some deadwood to cut out and mulch should not go up to the trunk. It can rot the stem. You should prune and feed roses after each bloom cycle.
Happy gardening in Hawaii. Gardens are where people grow.