We bought & planted 2 hydrangea PGs about 4 feet apart about one 1/2 weeks ago. They were both planted with the same fertilizer & get the same sun (morning) & shade (afternoon), but one is growing perfectly & the other has areas where all the leaves on a stalk are turning brown, even though there are flower heads on the stalk (but more heads are turning brown on this bush than on the other one). I was told to scrape a tiny section w/my fingernail & see if the stalk is green underneath (meaning the plant is still alive. I did this in a few spots having the brown leaves & all the stalks were green underneath. I have no experience with this bush, so I will welcome advice.