Slimy or mushy texture
Strong sour, rotten, or off smell
Dark, wet, or moldy spots
Stalks that are very limp or shriveled
Tips that are mushy, black, or slimy
Yellowing or browning throughout
Stalks that feel hollow or excessively dry
Visible mold
Ends that are very dry and woody
Any signs of spoilage after being stored too long