First up, deny them a welcome mat. Pigeons love flat, open spaces where they can sunbathe and plot their next attack. If you have a birdbath, fill it only half-full or add floating toys—pigeons hate unstable footing.
Also, cover any exposed soil with netting or lightweight row covers until your plants are established. Pigeons are lazy; if they can’t land easily, they’ll fly off to bother someone else’s garden.
The Spicy Solution: Spices & Scent
Pigeons have a highly sensitive sense of smell, and they despise certain spices. Sprinkle cinnamon, cayenne pepper, or crushed black pepper around your plant beds. Reapply after rain, and you’ll create a fragrant barrier they won’t cross.
Better yet, make a “pigeon punch” spray: mix a tablespoon of hot sauce with a quart of water, add a drop of dish soap, and mist your plants. The smell fades for you, but it’s a permanent “do not disturb” sign for them.
Pigeon Deterrent Garden at Jeramy Phillip blog