Dying rhodo
By Home198169
United Kingdom 
We have a rhododendron in a large pot in our garden and this year it has not flowered properly (very small flower as opposed to large, beautiful flowers up to now). We, therefore, chopped about 25% of the root ball and re-potted with new compost etc. Still the leaves are gradually going yellow with brown spots on the edges. Help.
11 Sep, 2013
Hi, welcome to g o y, if you have a rhododendron in a pot, the last thing you want to do is cut the roots off, it would have been much better to repot it into a larger pot, with ericaceous compost, but having said that, it would be much happier in the ground, and if you don't have acid soil, dig in plenty of ericaceous compost, and feed with sequestrine or similar 2 or 3 times per year, these have large roots which want to get down in the soil, so will never achieve their potential in pots, Derek.
11 Sep, 2013