I have a flowering almond in full sun, average garden soil (clay). It's at least 35 years old and has flowered poorly for the last couple of years. There are a lot of dead branches on it (or apparently dead with one small live branch). I did prune it last summer after it flowered (cut out obviously dead wood, shaped it a little), but it hasn't improved. Would a flowering plant fertilizer help next spring's display? Any suggestions?