I have just tried my first bit of gardening and I think I've managed
to kill 6 pyracantha shrubs within a week. I have recently moved house
and have my first ever garden. For a bit of protection I have planted
6 orange glow pyracantha but they all appear to be dying. They were
all about 2 years old with 2-4 branches each about 30cms high. The
shrubs are in the sun most of the day. I only planted them a week ago
but within days I noticed leaves yellowing and starting to fall off. A
few are worse than others. I've done a bit of research and found that
I have made plenty of mistakes

I dug the holes about twice the size of the roots. I put a layer of
compost down in the hole but then made my first mistake. I didn't
untangle the roots in anyway after taking it out of the pot. I set
them pot shaped on top of the compost. The soil that I removed was
extremely stoney so I ended up putting between 40%-80% multi purpose
compost back into each hole mixed with the soil. I presume that this
may be too much and I should have used topsoil? I put some wood chip
mulch down around the base of plants to keep the moisture in and there
has been plenty of rain in the last week.

I didn't add any plant food initially until I noticed the leaves
yellowing and falling off. After I noticed how yellow they were
getting I went and got some miracle grow which I added 6 days after
planting (yesterday). Every plant has lost many (10%-30%) leaves and
about 80% of the surviving leaves have a slight yellowing. Is there
any hope for these? Is there anything I can do at this stage? Thanks
for any help.

Badbark.