What has happened here?

I moved this mahonia about two years ago as the spot was too dry. It seems happy enough but slower growing than I expected.
As you can see from the pictures whole leaves/parts of leaves have died.
Could this be wind damage? (It lives near the side path of the house) or too dry? (surely not!!)
Any suggestions gratefully received.
Also, can I trim the partially dead leaves or should I cut the whole thing off?

 

I suspect it's too dry, many of these Japanese/Chinese plants grow as understory plants in temperate rainforest type environments. The types of plants you'd expect to grow with it are Rhododendrons, Azaleas and Fatsias etc, but if it either gets too dry or gets too much sun it may well come out like yours shows.

 

Hmm!
Mahonia also come from North America./also Central America.
eg Mahonia aquifolium, common name Oregon grape.. is from North America.

Growing conditions needed for Mahonia...
"Moderately fertile.
Humous rich.
Moist but well drained.
Prefer full or partial shade.
But will tolerate sun if the soil is not too dry."

I would trim any dead leaves off.

 

Yes they originate from the Pacific coasts, one on the American side ie Mahonia aquifolium, and the Mahonia japonica (from China) as shown above.

Mahonia aquifolium with its shortish leaves (actually is happily self seeding here, as the climate of Northwestern USA and northwestern Europe is fairly similar) which grows in redwood forests?



and Mahonia japonica which is Fuchsialadys plant, which grows in temperate rainforests.



Shade is very good for them, it maintains theit dark green glossy looks.

I have to be honest and say I'm not a great fan of the Mahonia look, but one thing that bowls me over is their heavenly scent in winter/spring.. I love it!

 

I have a fairly massive, (it would be bigger if I didn't cut it back every other year), mahonia "Charity", it just grows.

I took some cuttings a few years back which I planted under a laburnum, it gets very dry in summer and almost total shade.
The main plant is in full sun and out competing a lot of other shrubs for moisture.

Fuchsialady on your plant it look like frost damage to me, so just cut off the damaged parts of the leaves.
The other thing is, how did you know the original place was too dry?
Stop moving it around, and let it get a foot hold.

New growth should make it look better.

 

Ok I hasn't really thought of frost damage as it's been around for a while.
I have only moved it once. It was near a large tree and in front of a leylandii hedge. It hardly grew at all, but it hasn't exactly gone mad in its new place. Maybe it's slower growing than I expected. Bit disappointed really. Maybe need to read up more before I spend money!
Thanks for your help everyone