Question
I have two pink spirea bushes that get pretty pink flowers for a week and then
they turn brown.  I have positioned so they get some partial afternoon sun
(they are shaded partly by a pine tree.  I am willing to move them both if you
think there is a better place.  I am near the NJ shore and have sandy soil.  
Help!

Answer
Hi Kathleen,
thanx for your question.  There could be a number of reasons for the browning of the spirea flowers.  It's not the partial shade though, the shrub will bloom more profusely in full sun but does not mind a little shade.  It sounds like the plant may have fire blight.  Did you notice if there is any discoloration or wounds on the woody stems?  Do the flowers quickly turn brown and shrivel and then take on an appearance as though they have been burned?  Fire blight is an organism and will attack spirea.  You have to remove all of the diseased pieces of the plant and burn it.  Treat with a copper based horticultral agent available at your local nursery.  As your nurseryman for assistance.   Brown flowers can also be the result of aphids which can be easily washed off the shrub with a strong spray of the garden hose and use of insecticidal soaps.  Remove spent blossoms and you will probably get another wave of blooms later in the season.  I hope this helps.
Tom