The summer before last I planted some emerald cedars (about 3 feet
tall) in my backyard. Alas, being fairly inexperienced, only later did
I realize that this might have been a poor choice of shrub/bush for my
garden. I already lost one of the bushes last summer, and now am
seeing a few of the other bushes developing similar symptoms. I want
to transplant the bushes to a better location, so I'm looking for
advice on how to best do this to maximize the chance of the bushes'
survival.

Some info:
- I live in Toronto, Ontario
- the ground is aweful: about a foot down from the surface it is all
clay... rock solid when dry, and nearly impervious to water when it's
raining
- that means that when it rains the water doesn't really sink deep
down, but rather is trapped in the one foot (or less!) of soil between
surface and clay, and furthermore, when it drains downhill, it tends to
accumulate in the soil-filled holes in which the cedars were planted;
after a heavy rain it is quite common for there to be standing water in
the valleys of the backyard
- as recommened by the planting instructions, the earth around the
cedars has been covered by about 1" or 2" of mulch; I think this just
made things worse as it prevented any water accumulation from
evaporating...
- in fact, the cedars ended up growing roots in the mulch... I suspect
some of them have survived only because of this...

Hence what happens is that the roots rot, the foliage goes, and it's a
downward spiral from there. I'm starting to notice the tell tale signs
now on some of the other cedar bushes: brown and dying branches. Sure
enough the earth is very moist, and the mulch has been hiding some
standing water after a recent heavy rain.

To try to rescue the plants I want to move them to a different location
which is uphill and has a significant slope (i.e., draining). What
precautions can I take to ensure highest chance of success? Best time
of day, weather conditions for this? Should I allow the rootball to
dry out first before replanting? Heavy or light on the fertilizer when
replanted? What to do about the mulch-entangled roots, the ones which
might be the healthiest on the plants?

Any suggestion and advice would be most appreciated by this gardening
newbie...