I saw some of this on a plant of my mother's. I wiped it down with rubbing alcohol on a cotton pad and q-tip, and have been spraying every few days with a 50/50 mix of water/alcohol (I do this out of direct sun, and allow it to dry well before putting it back in the light). It hasn't recurred, but it's too soon for me to say I was successful. Definitely let the plants get somewhat dry before watering each time. Good luck!

repot now. The over watering brought the mold and is killing your plant. you can take it out of the pot carefully rinse away everything that will rinse away. Pit it on a paper towel and wait for potting instructions. I do not grow phals but plenty here do. It can stay out of the pot for days but I do not think it will be long till some ideas flow in. It is under stress now. Out of the pot will start the healing...It is possible it is the living dead. Meaning looks good but too much damage to the roots. Out of the pot for now.

Also make sure you separate those Orchids from your other plants mealybugs can easily spread to other plants!!!

That's not mold. The white marks you see are mealie bug eggs. The alcohol soap mix will take care of the adults. You will want to use a systemic insecticide, the babies are tiny and will hide on the roots and deep in the folds of the leaves where you can't see them.

Hmm. Any recommendations on the systemic insecticide for mealie bugs on orchids? I see Neem extract and other suggestions over here:

http://forums.gardenweb.com/discussions/1555452/phals-have-mealy-bugs?n=22

My large jade plant had a bad case of mealiebugs and the only thing that got rid of them was neem oil diluted with water. I put it in a spray bottle placed my plant outside in the morning and sprayed it good! Then let it set in shade to dry. Didn't harm the plant at all. Maybe you should do a test spot on your orchid first before spraying the whole thing to make sure it doesn't harm it.

Neem oil is good for insects and is said to have some anti bacterial properties as well. Most off the shelf OMRI products you find in the store will contain Neem. You can also buy raw Neem and mix it yourself, it's an oil so you have to mix in some soap to mix it with water. Even with soap it will separate so shake the bottle often. You will also notice a stronge nutty scent that will linger a few days. I don't mind it but my wife hates it.

Bayer makes a few products that will work as a systemic. They have a 3 in one product for roses I like to use. It comes in a large bottle so you can use it in the yard as well. I mix the product in a bucket and let the plant soak in it for 10 to 15 min. I then spill the left over on my roses.

My system for dealing with scale and mealies is:

Wash off everything you can see with a hose or the sprayer in the sink. A strong blast will knock most of them off. Probably a good time to repot, throw away the old mix and rinse the plant bare root.

Outdoors only! Soak the plant bare root in a systemic insecticide for 10-15 min and then repot. Wear gloves and leave the plant outside for a few days.

Follow up with a weekly spray of a soap water mixture. I use a natural soap, something without a degreaser. I like shampoo, something with coco butter or natural oil. You can also mix in Neem and alcohol but I usually just use the soap . It's quick, easy, smells nice, and you can use it with worrying about chemicals.

@James AKA lumpy_j(NJ 6) Thanks for the expert information!!! :)

@James AKA lumpy_j and others, many thanks indeed. They are already looking a little better. Photos to follow.

To @James AKA lumpy_j my Dendrobium keeps getting these spots on the leaves are they sunspots or fungus?

I don't think they are from the sun because of the placement on the leaf.

What they are is hard to say. My guess that there is a problem with the growing conditions that is stressing the plant, which then allows fungus or bacteria to move in

I would recommend going to the AOS web site and watching the webinar on orchid diseases

I would also recommend starting another thread, you will get more viewers. The more info you provide the better. Temperature, humidity, light levels, potting mix, watering regiment, etc, will help figure out what's going on.

If you treat the plant don't use copper based products on dendrobiums.

Thank you!!! It's a newly purchased orchid. I've only had it for a week so maybe it is stressed I will repot it and do what you recommend. I've been online trying to figure it out on my own meanwhile the Den. lost 3 leaves already. Really appreciate your input. Thanks again!