never heard of a rose slug in zone 5 ... but i dont know beyond that ... you west coasters have a slug for everything.. lol ... there is a rose forum .. they may have a more precise answer ... ken

It could be a number of things, insect damage, sunburn or a disease. Can you get a good focused photo of a leaf with the spots on it? And the white growth too.

Spider mites! See the fine webbing all over the foliage and stems? Spider mites suck the sap out of the plant, drying it out. It's like you having a bleeding ulcer. DO NOT FERTILIZE the plant! It is similar to it having been severely dried out, so it is water stressed by the mites sucking out more water than the plant can take in. What you want to do is wash the whole plant thoroughly. Turn on the hose to a trickle, put your finger over the end to create back pressure and raise the pressure of the stream coming out, then, using that strong stream, wash the leaves completely. Wash the stems completely. There are miticides which can knock them down, but they are expensive and can be toxic to you and your pets. If you remove all the foliage that is going to fall off anyway, then thoroughly wash the whole plant with that strong trickle of water, remove the fallen foliage and any other litter/debris from the pot surface, it will drown many of them. Mites like hot, dry, dusty conditions, which your plant receives against that hard scape. You need to mitigate them by cleaning the plant and its surroundings, then raise the humidity with the washing. Getting the whole plant wet will also more quickly rehydrate the plant. It won't take but a few thorough washings to kill off many of the mites and strongly encourage the others to move on. You should probably do a similar washing to the other potted plants on your patio. If the mites have found this one and taken residence, they very likely are on the others, too, waiting for the conditions to favor their explosion. Spider mites are something virtually everyone with hot, dry, dusty conditions deal with and they CAN easily be taken care of simply by several good washes. It will take some effort and you might get a little wet, but it's cheaper and much more "green" than any miticide. Once the plant starts putting out healthy new growth, you may resume fertilizing. As long as the plant looks 'scorched', it's water stressed. Fertilizing a water stressed plant can easily burn it further. Clean it first, get it back to normal then you can get back to your normal routine. Good luck!

Mine are probably too hot and dry, it's terrible out there =D I've got enough of them to start moving them around to find what they like best, so I think I'll do that. It's probably a good time to do their re-pot and check out roots anyhow. OP: From your description, if your mix only recently started to feel dry, I'm wondering if it's staying too moist for too long. Maybe stick a chopstick down in there and if it comes out with crumbs or damp, don't water. Wait till good and dry and chopstick comes up clean. I have mine potted up in an older version of gritty mix that I've had mixed results with. (whispers through gritted teeth) Damn you NAPA oil dry I'm going to unpot and check out what I've got, going to repot in straight pumice. Winter time in NY means lower light situation for all plants. Less light, means less water the plant will take up, this results in a mix that stays wet for longer than it should. This can be difficult on Adenium, as they easily survive less water than more. If I may, I'd suggest a change of potting medium before winter rolls around. I think there's an adenium board on here too....you might want to post there.