I transplanted 5 small hydrangea shrubs (Forever and ever, Endless Summer) which had not been doing well because they were in too much shade. I live in Syracuse NY and transplanted them the other day. Probably should have waited until the fall, but I wanted to make the change. Three of the plants seem to be doing ok, but two are in terrible shock. I've been watering all five twice a day. Will the two that are not recovering from shock die, or will the roots survive and the plant come back next spring? If they have a chance to survive, should I cut all the leaves and stems the two that are wilting?
First, construct some shade for the struggling bushes today. Use a large container, a sheet secured to sticks or leaf bags over a shovel. Anything will help. Mulch 3 inches deep; do not use rocks as mulch. They heat up in the sun and will bake hydrangea roots. Do not trim the plant unless a stem has died. The shrub is distressed and needs all the energy production from leaves that it can get. Often, the tiny roots that absorb water are the farthest from the plant so when plants are dug up, these are lost. Next time you face a similar situation, remember the old adage for perennials, including bushes: 1st year sleeping, 2nd year creeping and third year leaping. This refers to top-growth. The main job of a first year plant is to get roots established. You may see zero growth above ground. That's OK because until there is a good root system, the roots can't support further top-growth. Don't fertilize your struggling bushes until they recover. It is an understandable instinct but fertilizing acts as a signal to plants to grow leaves. Your shrubs need to focus on roots and recovery.