We don't get much rust here in NJ, unless it come in imported on a plant via mail order. Rust looks like the orange dust from Cheetoes/Jax corn curls. We are more likely to have blackspot or powdery mildew. Your plants have blackspot. Age of plant doesn't matter, some varieties are less resistant to disease. By "Bayer rose fertilizer" do you mean one of the Bayer Advanced combination products (fertilizer/insecticide/fungicide)? These are not effective for blackspot control. The fertilizer isn't enough, the insecticide kills worms, and the fungicide can't be effective in time to prevent an outbreak of blackspot. For effective blackspot control, try Bayer Advanced Disease Control for Roses, Flowers, and Shrubs. It is a fungicide only. This can be started now, applied once a week until the disease is under control, then every 10 - 14 days. You can use a small spray bottle, and measure the product accordingly. Next year, start your fungicide treatment about a week after pruning in late March/early April. Make sure that the plants have been watered well before applying the fungicide. For fertilizing, try Espoma Rose-tone or Espoma Holly-tone. These are organic, and they also provide amendments to the soil. I also apply a layer of composted manure in the fall. Also, check the amount of water that the plant is receiving. Roses like to be watered deeply, and less frequently. The top of the soil may look moist enough, but the roots may not be getting enough moisture (even with the rain we've had this spring).

Direct sunlight would be outside in direct sun. The sun coming through your windows is already going to be filtered light. It would be very good for your tree to repot into a container with drainage, use something like the 5:1:1 mix and place it right up in front of a southern facing window where it recieves as much light as possible. I grow quite a few ficus benjaminas. They have the same general needs as your tree. Naturally, these trees want as much light as possible. Anything that says they don't like direct light is false. It's just that indoor grown leaves can't handle full outdoor sun unless acclimated. In the winter months, I keep the tree in front of a southern facing window with the addition of grow lights. I have five 55w (250w equivalent) 5500k grow lights above the tree. In the summer, I acclimate the tree over a span on a couple weeks and then place it in full direct sun all summer. That is when it puts out the most growth. Literally grows a couple feet every summer. the tree is 7 feet all and was under 4 feet tall when I got it a year and a half ago. Currently in an 18" terra cotta pot in Al's 5:1:1 mix.

they do go dormant with lower temps and lower light and drop some leaves (sometimes all). But they won't if you keep them even in winter at least at 70F. 75F would be better still. they grow best in heat at 80-85-90F and lots of water and humidity..which you can only get outside in summer, unless you are subtropical.. I wake up mine by putting them on heat mat, keeping them moist and ultra humid in plastic for at least a month. Until they start sprouting the 1 st leaf. without the heat at the roots they won't wake up. keep them dry until you can do that. if you water them at 65F and below the tubers will just rot. the tubers can go dry in the pot for sev months depending on size (the larger ones can last 3 mo, the small ones better to wake them up earlier).

I am having the same issue. It is so early isnt it? Like you say , not all but definitely several. It is almost prunning season here in southern Oregon, a couple more weeks and then Crossing the fingers that we dont get a late frost