Don’t leave a dump on this stump.

A furious Carroll Gardens resident had enough with dog owners who don’t tidy up after their pooches relieve themselves in a tree pit outside his Hoyt Street home, so he painted a foreboding warning on a tree stump urging pup lovers to keep the neighborhood’s de facto doggie potty clean — or face some messy repercussions.

“If I catch you it won’t be pretty,” the stump now reads.

Lou Femenella takes credit for the message, which he says was necessary since the stump became a dog poop hot spot after city workers tore down a dead willow tree between President and Carroll Streets.

“It’s appalling and selfish that all these people just leave their dog poop in front of my house,” said Femenella, “It’s not right.”

Femenella isn’t angry that dogs frequent the stump — he’s angry at the pet owners who don’t pick up after their pups.

“It’s a snowball effect,” he said. “People will walk by here with their dogs and see that other dog walkers have left their dogs’ poop here. And then that dog walker is going to think, ‘Look at this nice patch of stump,’ and then get it in on it. It’s ridiculous!”

And some dog lovers agree, saying they have no problem with Femenella’s warning because it’s targeted at bad-mannered dog owners, not the dogs themselves.

“It’s a good thing,” said dog walker James Huffman. “When I see broken glass and nails in areas that are supposed to discourage my dog from being a dog, I get angry. But if people aren’t simply picking up after their dogs, then I think it’s good. People should pick up after their dogs.”

The threat has helped keep the tree pit cleaner — but the message has also had an unintended effect.

Femenella says he regularly sees passersby, some with dogs and some without, stopping to take pictures of his message, pointing at it, and laughing at it.

And that won’t change anytime soon — a Parks Department spokesman said that there are no plans to remove the tree stump.