Your Gardening Questions Ed Hume cannot answer all of the garden questions he receives, but questions of general interest will be answered here every month. Be sure to check the index of previous questions and answers . Many problems have been dealt with there. Transplanting Rhododendrons Fall is fast approaching, and I have to move a rhododendron about 4 feet tall, with a 4 inch dia stem which has been in place for at least ten years, to another spot in the garden where two other rhododendrons are flourishing. I'll probably have to release it from its present position with a line to the truck, unless there are other methods that may be more effective and provide less of a shock to the root system.
Rhododendrons generally have a fibrous root system and are among the easier plants to transplant.
Start digging at the drip line of the plant and continue inward until you reach the dense fibrous roots. That will give you a sense as to how big the root ball will need to be. You must move the plant with soil attached. Prepare the new planting soil with compost, peat moss or processed manure. Provide sufficient drainage and the plant may need to be staked the first winter.