Griselina Littoralis (N.Z. privet) - leaf symptoms
 

I obtained a couple of Griselina Littoralis shrubs (a.k.a. New Zealand
Privet) about 9 months ago. Shortly after aquiring them, I repotted them
into much larger pots and they did fine for six months. Then I repotted
them again into even larger pots using John Innes No.3. This was about two
months ago.

Very recently, I have noticed that many of the leaves are turning brown at
the tips. A few have turned entirely brown and are easy to pull off. Some
are turning yellowish. Here is a photo:

http://www.aalife.com/gris.jpg
http://www.aalife.com/gris1.jpg
http://www.aalife.com/gris2.jpg

Can anyone suggest what the problem is? My book on shrubs suggested frost
damage or root waterlogging. We have not had any frost, and while I have
occasionally soaked the soil thoroughly when watering, there are holes in
the bottom of the planters, so I wouldn't have thought that waterlogging
was an issue. John Innes No.3 is fairly well-draining, isnt it?

I know these are inexpensive plants, but they serve an important purpose
for me - or will do when they grow bigger...

Thank you...

Al