What to spray outside to reduce indoor spraying

I am pretty sure one of the primary reasons my big kitty is spraying inside is related to outdoor kitty smells.

My cat is an indoor cat and the spraying becomes worse in the spring when the outdoor kitties start roaming around.

Is there something I can spray around the outside of the house to reduce the other kitty smells in hopes of reducing my cat's spraying indoors?

(He is neutered and recently checked by the vet.)

Thanks!

I've had some luck with basil plants outside windows - either in pots, or planted in beds. They've been enough to keep a neighbor's cat (neutered) from spraying outside the windows, which was leading our cat (also neutered) to do the same thing inside.

There are also "P**s Off" plants (that's literally what they're called) that you could try.

put together a concoction of white vinegar and lemon juice. Spray it around outside. Cats hate the smell of that stuff and it combats the scent. I did that cos Oscar kept coming in stinking of tomcat spray - wasn't his cos he's been done, and even prior to being done he didn't spray. But the horrible little muffins round our area kept spraying around Oscar's territory. He'd go out, have a roll around in the garden and come in stinking. So I made a bottle of that stuff up, sprayed it all around the house and over Oscar's house in the garden. Touch wood, they haven't been back!

I'd also recommend using a Feliway diffuser indoors to calm your cat.