>I have a friend with two rhododendrons that she planted about 4 years ago.
>When she planted them they were small and neither had flower buds. Since
>then, the plants have more than doubled in size but neither plant will
>flower. Is there a reason for this? And is there anything she can do to get
>the plants to produce flowers?
Without knowing which species she has, I would say the problem could likely be
too much nitrogen in the fertilizer and not enough phosphorus. That alone can
inhibit flowering in most things. Food for flowering plants should have the
middle number on the package larger than the other two (the ratios are given
as N-P-K). You might also check with a rhododendron expert to see if your
particular plants have any cold requirements.