Sorry to hear about the knee, Mollyata. And
Your tree is a Japanese Maple
Acer palmatum. it could be the variety 'Garnet' but there are other similar red JMs and I don't think your tree can be positively IDd from your photos.
Japanese Maple (Acer palmatum)
I also suspect heat, as Lucy suggested. You didn't mention your weather this summer, but much of the country has suffered unusual heat waves. I question your watering schedule; although JMs do like soil on the moist side, twice a day sounds excessive. How long and how much water do they get each time? A deeper soak less frequently allows for healthier roots.
Here is a good guide for overall JM care
https://www.thespruce.com/japa...
Japanese maples and roses have very different cultural needs. The maple can be quite happy in half shade. Although knockout roses are known for being very resilient, they want full sun and less frequent watering. Soil pH and fertilizer needs are different also. Interesting landscaping decision by the previous owners.
About knockout roses
https://www.knockoutroses.com/....
Also, you would do well to post about the rose separately on our roses forum. Lots of experts there
https://garden.org/forums/view...
Btw, you might want to Google what you typed earlier —palladium garnet. Maybe you got autocorrected?
