Plants wilt and die slowly when their roots become compromised. There are several causes of this: 1) Root strangulation. This is best prevented by proper root pruning when planting. If the plant is not too far gone, it might be rescued by digging and removing the soil. Then cutting any circling roots that may be strangling other roots. The roots need to be opened up. On larger plants, some of the top must be removed to compensate for the weak state of the roots. Any time the roots are exposed, they must be kept moistened. Roots that dry out will die. 2) Phytophthora Root Rot or wilt. This root rot is the major killer of rhododendrons and azaleas. It develops when roots are growing in wet conditions. The rot is more prevalent in warm summer conditions. Plants infected with crown rot caused by the oomycete, or water mold, Phytophthora have roots which become clogged with brown oomycete, or water mold, internally. The roots get blocked and the plant wilts and dies. There is not much of any cure for crown rot. Some varieties of rhododendrons are vulnerable (Chionoides, Catawbiense Album, Nova Zembla) and some are resistant (Roseum Elegans, Scintillation, PJM). Sphagnum moss and bark dust combined with good drainage seem to prevent crown rot, but do not cure it. 3) Drought. It may have simply dried out. If you plant rhododendrons or azaleas in late spring, it is very important to give them some extra water while they are growing new roots. Never let the soil completely dry out' it's best to keep the soil evenly moist. Too much water or poorly drained soil might be another explanation of sudden rhododendron or azalea death. Rhododendrons and azaleas have very fine, fibrous roots that are easily damaged by waterlogging, even for short periods of time. 4) Voles. Voles, also known as meadow mice, may have chewed on the bark and roots near the crown of the plant. Sometimes they chew all the way around the trunk and kill the inner bark, resulting in death of the whole plant. Keep mulch away from the trunk to discourage voles. 5) Bark Split. The bark may also split when there are wide fluctuations in temperature in the winter. Rhododendrons and azaleas may begin to come out of dormancy if late winter weather is warm; if a cold snap follows, bark injury is likely, especially in sunny, exposed sites. 6) Wilt and slow death can also be caused by juglone poisoning from walnuts. Plants wilt and die suddenly is usually caused by roots which are girdled by larvae of the Black Vine Weevil, Otiorhynchus sulcatus, Strawberry Root Weevil, Otiorhynchus ovatus, or Twobanded Japanese Weevil, Callirhopalus bifasciatus. Adult weevils feed on the leaves at night except the Twobanded Japanese Weevil which feed during the day. Specimens may be collected during the day or at night for identification depending upon the weevil. The major damage is caused by weevil larvae which girdle the roots and kill the plant. Larvacidal drenches may be used to kill them but are of limited effectiveness. Foliar sprays are very effective at controlling adult weevils when leaf notching starts. Foliar sprays are very effective at controlling adult weevils when leaf notching starts. Foliar sprays must be repeated until no adults emerge. Twobanded Japanese weevils are apparently resistant to carbaryl (Sevin), diazinon, and malathion. Orthene gives good control when applied as a foliar spray and drench. Since weevils can't fly and spend part of each day in the soil and part of each day feeding, you can paint the trunks with Tanglefoot to stop them, but make sure no branches are touching the ground. To answer your question, I think the plant is terminally ill, but would still hold out hope a little longer. You seem to understand the basics very well. Here is a link that might be useful: Rhododendron and Azalea Problems

Sorry for the slow answer, but we've spent more time with doctors than gardening in the last week! The soil in the front bed is a little deeper than 6"; most likely about 8". The mix in the rear bed is 6" or less. Both are Mel's mix and open bottom on top of blackland clay. I fertilize with a mixture of synthetic 13-13-13 and organicc fertilizer as well as replenishing the compost component of the mix as the level goes down. The plants are on 8' plastic-coated metal stakes 1' apart. Next year I might plant them three across to prevent so much contact between the plants in an effort to prevent the early spread of disease. The tomatoes are strictly deprived of their suckers and the single stem is tied to the stake with jute twine. The fruit was so heavy this season that the fruit trusses were sometimes torn from the main stem, requiring more surgery with the jute twine. The harvest has been unreal!

Yes, the crack will scar over. Don't throw the fruit out unless it gets to the point where there's so much mold the fruit begins to rot. Try to keep moisture consistent as that will prevent future cracking; it doesn't look like you've mulched the container; if not, that will help. You can use almost anything as mulch, including shredded office paper, plain newspaper, or even cardboard.

Hornworms do not make a plant unusable. They reduce the foliage and the fruit. A plant can grow more and resume making food for humans. Trim off any areas that are really "eat up". This will reduce the number of open ended damaged areas where disease can enter. I would spray with Daconil to help with any disease organisms. You might want to add a bit of fertilizer with extra nitrogen (one time shot) to help add some foliage.