That distinctive pee smell emanating from your shed is a cat's way of advertising to other cats in the area. Males spray to lay claim to territory, while females spray to announce their heat cycles. Either way, it's not an odor you want lingering in your yard.
Clean Like Crazy
Before you can stop the frustrating feline from spritzing your shed with Eau Du Litter Box, you need to remove the smell that's already there. Cats will return to the same spot to spray time and time again as long as they can still smell urine there. You can't just hose the shed off, because that won't completely remove the smell. White vinegar will neutralize the odor, as will commercial products designed specifically to break down the enzymes in the urine spray.
Once your shed's been de-scented, you need to keep the cats from recoating the area with a new layer of stink. Cats don't like the smell of citrus, lavender or coffee grounds, so try sprinkling one of these around the area to keep the trespassing tabbies away from your shed. A plastic mat whose proprietary name is Cat Scat deters cats from entering certain areas through little plastic spikes on the top. The cats don't like the feel of the little nubs on their paws and avoid the surface. A carpet runner, the plastic or rubber kind with little gripper spikes on the bottom, flipped over and covered lightly with dirt will accomplish the same feat. If such measures keep cats from your shed, they can't spray it.
For particularly persistent kitties, you may need to go a little higher-tech with your deterrents. Motion-activated water sprinklers give tabbies a wet surprise when they venture too near. Ultrasonic deterrents emit harmless sounds only cats can hear to encourage them to move on.
Remove the Urge
Some cats just refuse to take the hint. If your deterrent efforts fail to convince kitty to move on, you may need to take more drastic measures. Neutering and spaying reduce cats' urges to claim territory or to advertise their reproductive status. For roaming cats, contact your vet or Humane Society office to see if trap-neuter-return programs are in place. Sterilization will solve your stinky shed problem as well as keep the local stray and feral cat population from growing.
Jane Williams began her writing career in 2000 as the writer and editor of a nationwide marketing company. Her articles have appeared on various websites. Williams briefly attended college for a degree in administration before embarking on her writing career.