After azalea and rhododendron plants have had time to settle in where you've planted them (see Page 3), the next step in azalea and rhododendron care is fertilizing. But even then, be careful not to over-fertilize. Stay away from the mentality that says, "If some fertilizing is good, then more must be better"! There are standard fertilizers for the care of azalea bushes and rhododendrons -- mixes that can be purchased at nurseries and major hardware chains. Follow the instructions on the fertilizer's label. Except perhaps for one instruction -- the amount of fertilizer to apply. Cut that in half! It is usually better to be conservative about applying fertilizer.
A good time to fertilize azaleas and rhododendrons is right after they have finished blooming.
Ally #1 in Azalea, Rhododendron Care: Mulch
Mulching is an essential part of proper care for azalea bushes and rhododendrons. The roots of these shallow-rooted plants need the protection that mulch affords against extremes of heat and cold -- and against drying out. Remember, the fact that these plants like a well-drained soil doesn't mean they like to be dry. Azaleas and rhododendrons are not desert plants; they like water. They just don't like to be sitting in it for long periods of time, which would cause their roots to rot.
The best mulches for azaleas and rhododendrons are acidic mulches, such as pine straw. For information on other acidic mulch choices, please consult Choosing the Proper Mulch. Since mulch eventually does break down and become a component of the underlying soil, you might as well go with an acidic mulch. There's no sense in fighting the acid-loving tendencies of azalea and rhododendron plants!