How can I keep cats from using my flower bed for their bathroom?

That's frustrating! You can put pieces of aluminum foil or jagged rocks, you can also sprinkle citrus peels. Cats like none of these- good luck!

Lavender and curry have strong smells that cats don't like. If you plant those among/near your garden it should keep the cats away.

bury some fine chicken wire just under the dirt..

Cayenne pepper! Sprinkle it everywhere...only downside is when it rains you have to redo. But they hate it!

A thought. Thank you

great! Rain is somewhat scarce around here, so I will try this. Thanks

Try mothballs, will keep cats out of flowers. Can't use them in veggie gardens.

I heard about this, but I didn't know about the smell of the mothballs.

I use old coffee grounds plus it's good for the plants and soil.

Great idea

Do not use moth balls. Citrus peels work along with plastic forks with the prongs facing upward and any plants with strong odors.

CHICKEN WIRE KEEPS THEM FROM DIGGING

,moth balls

The cats do not like to walk on chicken wire if you place it on top of the soil.

If you know the owners be sure to discuss the situation with them. Years ago my cats were using the neighbor's back yard (new neighborhood and they didn't put in grass). My cats started disappearing, one each Saturday. I was heartbroken... Years later I heard what was happening, and if the neighbors had discussed this with me I would have built a wonderful outdoor litter box, especially if it would have prevented the loss of my cats. 15 years later I still mourn them.

some are homeless, others the homeowners just let them roam

You can put moth balls inside plastic jar screw on lid lay on side & punch holes in side that's up safe from pets but let's smell out & rain doesn't melt them.

Nurseries sell bags of cocoa shells. I used this spread around my flower beds and had not one more cat in my garden! The shells are rough on their little paws so they don't like to walk on it and the odor is a deterrent. Because they are organic, they break down and nourish the soIl. Win-win-win all around!

Top your bed(s) with pebbles about 1" or so in diameter. You can rake them aside to weed or replant, then rake them over again. Cocoa shells or coffee shells work, too.