I doubt moss growing on a limb is the best indicator of the moisture in the soil (it may be a good indicator of humidity and moisture in your region). Transplant shock/wilt can last a full season or more but then I live in GA so our conditions are a lot hotter than you have. My new plants in the ground are watered at least every other day and sometimes every day to get the plant established in its new home. I often have to water them regularly for two to three years to get them on their own and in really hot, dry weather; supplemental watering can make a huge difference between a wilted bush and a lush full growing shrub. You can stick your finger in the first inch or two of the planting hole and see how wet it feels. If you suspect it is too wet, pull the plant out and move it to a new location that has better drainage. Mixing dry soil in a wet hole often results in more wet soil eventually. Do keep some soil over the top of the root ball though as the original root ball exposed to the outer air will wick away a lot of moisture. Mounding is difficult to keep the native soil on top at times as you have found out but is almost necessary for some fussy plants like rhododendrons.

Some stem browning out in the Fall is normal as the plants harden and prepare for winter but Lord, the stems should not be falling down if it is that. I would first check the soil moisture and inspect the length of the stem -including the area where it connects to the base/crown- looking for signs of "damage" by insects (not likely but always worth a shot). The alternatives are difficult to identify without technical help. Root rot can make the stems loose color as the roots decay and then the stem browns out albeit root rot tend to a-l-s-o cause leaf issues like wilting, which you do not report. Odd that root rot would not cause leaf symtoms. Note that if it is root rot, leaf wilt may happen once the stem browns out near/around the leaf's petiole. A non scientific test for root rot is to see if the soil is wet for long periods & to extract the plant and check the roots, even smell the roots. You can do that to one of the worst ones since pulling it out will affect the look of the hedge so think about whether you want to do that or take it for analysis instead. See the info on Phytophthora Root Rot below: http://www.aces.edu/pubs/docs/A/ANR-1212/index2.tmpl Another fungi called corniespora (Sp?) can cause stem rot in hydrangeas, albeit very rarely and it tends to make leaves wilt too. There are fungicides recommended but I am not sure if this is your issue since your notes did not mention leaf wilt. Bacterial pathogens like pseudonomas can cause either leaf spots and-or stem rots on hydrangeas. There is no easy way to diagnose psedunomas as Agric Extension Folks are the ones who have the equipment to detect/identify it. The usual clean sanitation practices are recommended as well as the destruction of infected plants and use of copper fungicides. So, I suggest a quick trip to the nearest Agric Extension Office with a sample in a tightly sealed transparent bag since this is spreading so fast.

More hydrangea woes! I have an Annabelle hydrangea that is about two years old. Last week I noticed some white stuff on one of the leaves. It looks too stark white to be powdery mildew so I asked a garden centre. They had suggested it was insect eggs so I removed the leaf affected. Coming home today two more leaves have substance on them and I noticed a small caterpillar (see photos attached). I looked up the leaf miner but it doesn't seem to fit that description either as none of the leaves are sewn together and the caterpillar doesn't have a brown head. Does anyone know what this could be and what the best plan of attack is? I'm worried that the neighbouring plants will suffer if I don't remedy this soon. Thanks!!!

Looks like some leaf powdery mildew in the first few pictures. The blooms may be spent and that is why they are turning pink/brown although lack of enough water can trigger early browning of blooms and browning of the leaf edges moving inwards. The stems look fine. The brown dots on the stems are lenticels, normal on hydrangeas. Some varieties have more or less than others so just ignore them. Avoid overhead watering as much as possible in order to minimize the chances of getting cercospora leaf spot. I did not see signs of this on the pictures. If you use a sprinkler, set this station to water 6-8am so the leaves are not wet for a long period of time. You can try treating the PM with a spray of 40% milk and 60% water every 7-10 days (discard unused mixtures; spray both sides of the leaves and all branches and stems) or with a fungicide for PM like Immunox. Maintain 2-4" of organic mulch around the plant at all times. I could not clearly tell (from the pictures) if you have woody stems or dead stems. Dead looking stems that do not leaf out by the end of May can be pruned all the way down.