Answer: Your flowering plums should have flowered by now and developed leaves on the branches. The suckers growing from the base of the tree indicate the root system is alive, so perhaps the branches suffered some winter damage. Scrape the bark with your thumbnail to see if there is any green tissue directly beneath the bark on the branches. Green tissue indicates live wood, which means your tree is capable of producing leaves and probably will later this spring; brown tissue beneath the bark indicates that portion of the branch is dead. Keep scraping until you find green tissue. If you can't find any, the branches are dead and the tree should be replaced.
Best wishes with your plum trees!
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