Anytime you see black leaves, think too much water. First, to try to save the plant, move it to sunlight..a western or southern exposure would be recommended. If you believe you have indeed overwatered, then you have to unearth it to inspect the roots. Plants need water only when they need it....not when you decide to water it. Even when you faithfully don't water too much, maybe what you have given it is too much. Once the plant is out of the pot, inspect the roots for signs of rotting. Put your nose to it. Does it smell gunky...do any of the roots come away easily. If this is the case, wash all the soil off around the roots. Re-pot using fresh potting soil (or a soiless mix) and be sure to put something between the drainage holes and the soil. Shards of clay, stones of size, are just two things...and there are many other things you can choose, to keep the soil away from plugging up the drainage holes. Houseplants must drain after every watering, then allowed to dry down between. On the stairwell. Lots of light...but not direct light. That speaks for light from a fluorescent or incandescent light bulb up on the ceiling. Not good enough. Light from a non-natural light source must be within 6 - 8 inches of the top of the plant to be effective. Move the plant to natural light however what room it goes into. Maybe you put it on the stairwell for decorative purposes. Unfortunately, your plant does not have your house's decor in mind to live its life. It needs light to survive. Light and proper watering and food when it is growing. Never feed a plant that is not growing or is sick. If you feed the plant, water it first, then feed at reduced rates until mid February/March when light levels return. If you just cant bring yourself to tkae the plant away from how it improves the look of the stairwell, think artificial. There are any number of real plants that look exceptional --but are plastic. Michaels and their ilk, have many plants that you will fall in love with and can do wonders for home decor.

Sounds like mealy to me, too. Since you can take outside, can you also hose leaves? If so, spray foliage. Let air dry. Using a Q-tip or cotton ball, and rubbing alcohol, dip or coat tips/balls w/r. alcohol, then swipe off as many white lumps as possible..Continue this procedure. If you have a mister/sprayer available, add 1-2 capfuls of rubbing alcohol to water..14-20 oz of water. Spray thoroughly, over and under leaves..Spray w/this mix 2-3 times per wk for 2 wks. They also sell organic insecticides to kill mealy. D. marginatas do not like sitting in wet soil or being overpotted..(especially if soil is too heavy and retains water) When repotting, it's best increasing pot 1-2 sizes up. Use a well-draining soil. If you don't want to mix your own, buy a Cactus-succulent soil. Give a drink only after soil feels dry. Hope you rid those mealy...Toni

Kristi, potting down to a smaller pot that fits the size of the roots is a good idea. By 'regular' potting soil I'm assuming you used one of the lighter peat-based mixes, which is far better than the heavy, dirt-type soils. I would have recommended you mix some perlite with it before potting, but let's see how it goes. Regarding the 3 tip cuttings, they're too dry and need to be rehydrated. They also have too many leaves which demand more moisture than the cut stem can take up. You should take most of the drooping leaves off, leaving 4 to 6 or so at the top, and put all the cuttings into water for a day to rehydrate. To 'hedge your bets', I would leave 1 in water and put the other two back into the vermiculite/soil medium. Or vice versa. If leaves of the ones in soil droop again after rehydrating, put the pot into a plastic bag or invert a glass or bottle over it to retain extra humidity. If the bottom of the stem of the cutting in water appears to be rotting, cut it back to good tissue and change the water. The main plant is also seriously dry, and all those leaves will continue to lose the moisture left in the stems and trunk. So I would cut most of those leaves off, as with the cuttings. If the long, stringy roots came apart in fragments and didn't hold together during the handling of the repot, they were rotted. It's hard to tell 'healthy' from the color, but rotted roots would be dark brown and might have an unpleasant odor. There should have been at least some larger roots that were fleshy and light colored if they were healthy, did you see any of these? Please squeeze the stems of the main plant at various places. If they are spongey and not hard and firm, rot has moved up the stem to that point. Good tissue can also be determined by lightly scraping the surface of stems, rotted tissue will be dark and the outside bark will come away easily, healthy will be light colored and firm. Let me know what you find. Russ

Cutting back to "nubs" is essentially how this plant is handled for propagation as well as regenerating plants that grow too tall or too lanky. The top growth is likely to rot completely - just not at all frost tolerant - but the roots may have survived. And if they have, cutting back to a nub will allow the plant to reestablish itself. But it will take time. Don't feel alone :-) I too have left summer vacationing houseplants outside too late and have had them nipped by frost. And just a moderately light frost...not into the 20's!! They were all toast, including a huge Christmas cactus more than 30 years old I inherited from my mom :-( I still have to bring mine in for the winter - that is on today's to-do list!! Been meaning to do so for the last couple of weeks but the rains have hit and I've been busy with work stuff. It ls chilly here at night - in the 40's - but nowhere near frost temps.