Yes, they can be pruned, but regular pruning to keep one within bounds is really not the way to go...better to have a shrub that reaches an acceptable mature height for your site. Rhododendrons come in all sizes and it would help to know the name of yours before deciding if it will potentially be a problem...do you know which rhododendron this is?

Pruning is best done immediately after flowering. These set their buds for the following Spring in Summer; pruning in summer will remove the next seasons flower buds.

If the plant is young like yours, you can guide its growth without pruning, merely pinching the leaf buds at approximately the same time you would be deadheading spent flowers in late Spring. As the leaf buds, which are slimmer and pointier than the fat, blunt tipped flower buds, begin to elongate and start to unfurl, take your fingers and pinch/break them off. This will encourage more branching lower on the plant - the result being a more compact, dense shrub.

HOW CAN I TELL WHEN BUDS ARE SET? MY PLANTS HAVE JUST PUT ON NEW GROWTH, AND I NEED TO PRUNE. IT'S THE END OF MAY,AND ABOUT 3 WEEKS PAST BLOOMING. AM I SAFE TO PRUNE?

The sooner the better. The flower buds will be setting in late June and early July. You want to prune now so you won't be removing next years flowers.

And Lorislines,

Rhododendrons are easy to move. Just remember they have shallow roots and be careful no to disturb the roots too much. Now would be the time to plant your white rhododendron in a place where it has enough room. Most varieties need more than 2' of room. If you are very luck you may have one of the very low growing ones, but the chances of that are slim. If you know the variety, we can tell you how big it gets.