Xref: kermit uk.rec.gardening:148455

It looks as if you have poor soil that is low in humus, when you replant the
Rhodo.. assuming it lives through it lifting... I would dig in a load of
peat into an area about 4 ft across and about 12 to 15 inches deep, rhodo's
are not deep rooted, then every couple of years give it a mulch of a couple
of inches of peat.
make sure that it doesn't dry out late May to early July as that is when
next years flower buds are initiated

--
David Hill
Abacus nurseries
www.abacus-nurseries.co.uk