Weigela
Symptom Cause  
Ends of branches die back
Cold Damage
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Swollen tumor-like growths on stems
Crown Gall
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Irregular tan spots on upper leaves
Four Lined Plant Bug
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Ends of branches die back
Frost Damage
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White, cottony masses on roots/stems, above/just below surface; plant wilts, yellows
Mealybugs
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Leaves discolored; growth stunted
Root Nematodes
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Leaves turn yellow and wilt
Root Rot (fungus)
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Branches; foliage encrusted with bumps
Scale
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Branch tips turn brown and die back
Twig Blight
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