Sunzim, you can appreciate that the leaves nearest any problem the soil has will feel the effects first. They would of course also feel the pain longer than the upper leaves that may indeed also come to harm from whatever the problem is/was. It just takes longer to get up there. Lower leaves, having dropped off, will never replace themselves. Surely you had some sign before leaf drop. Possible browning or yellowing of leaves or a pest has gotten into the chicken house. Leaf drop can come from one or a combo of causes. Under or over watering, too much sun, too much fertilizer, not enough humidity, (consider misting), and that drafty location you mention can indeed cause what the plant is experiencing. Warm air from above will cause the surface soil to dry out first. You touch the soil, feel its dryness, and so water. The soil down below though is still with water. Such drying of the surface then cause overwatering to the roots. It helps when the pot drains well and the water isn't allowed to sit in the saucer. By eliminating each, discarding any that doesn't fit, is the only way you can find and correct the problem. I have no idea how long the problem has been happening but you can also appreciate that sun values over a cold winter do not support growth on a plant. If you have perhaps fed the plant, in other words, encouraged growth when the sun cant support it, then such weakness of leaves will be the first to feel it and either do poorly or when push comes to shove, they drop off. Fertilizer should only be given a plant when it is growing, when it can use the food. Watering through winter, is also much less needed. The plant is not using water like it used to in its growing stages. Look for any sign of pests; on the leaves, in the crotches, in the soil. But, be sure to not go up more than one size---even with the addition of other plants in the pot--too much soil---or rather more soil than is needed, will force-feed the roots to take up food it cant use. The extra expanse of soil causes extra water to be taken in the roots which may not be able to use it. If this condition were to be continued for some time, the roots may begin to rot. Once that happens, the plant is unable to take up moisture...the lower leaves feel it first, eventually reaching up into the upper section.

It was planted this past spring in the ground. I have mostly red clay and sand soil here and drainage isn't super good but okay. There is slight slope for excess water to drain off so the roots don't stay saturated. When I planted it I mixed up the top couple inches with more sand and raised the planting area a couple inches higher than the surrounding area. Then a inch layer of home made compost topped with a couple inches of pine bark mulch. The root system seems fine. When I fertilized it a few weeks ago I pulled back the mulch to take a look and the roots were just below the mulch and spreading in all directions, nice and white too! I watered it once a week in the summer with a hose slowly for 20 min or so. Now that's it's cooled off every 2 weeks unless it rains. Here is a pic of a couple small branches that fell a few days ago. They were green when they fell but have started do dry up as you can see in the pic. They are only a couple inches long. This is we're they actually feel from on the tree Some new growth that decided to stay on Tips of the new growth. On one pic you can see where the new leafs aborted or just dried up? I assume navels are rather slow growing? Not as much growth as I am seeing on my satsuma, Meyer or rio red?

Many thanks. And, yes I agree. Looking at the heuch has me wondering about space limitation and I'm definitely lamenting the caladium as an addition. The Dr. was planted so that the crown was at least 2 - 3 inches below the soil line for winter protection. I just can't get over the fact that the new growth that peaked its head from that crown just flopped so quickly and I have no idea why the other buds on the old wood have failed to respond to the warmer weather. I just can't give up hope, even if it looks bad. I've had good results from moo poo or alfalfa tea bags when dealing with roses on their last leg. Perhaps it'll help heal the damage I may have caused. But if by the end of June there's no significant change, I'm afraid that may be it. Given that it is in a container and the fact that we had a harsh winter in DC, I'm wondering if the below freezing temps may have weakened it. If this doesn't work out and I'm really hoping it does, I refuse to give up on the Dr. b/c it's just such a beautiful clem and will plant another one in a container all on its own. Perhaps I'll do that next to this one just to offset what I've lost.

Not that I know of, my neighbor uses round up but his house is about 150 feet away from the plants. i am against the use of weed killer myself. Could roundup travel that far?