Spray a repellant directly on the bulbs or place screening over the bulbs before covering them with soil. They look similar to a mouse and are active all year long. They will eat anything green and will also attack the base of trees. Try wrapping the base of young trees in the winter to discourage them. Half fill an empty clear plastic bottle with water and lay it on its side in the area you want to keep 'cat-free'.
Cats dislike the changing reflections it makes in the sunlight. .
Group plants in the landscape according to their water needs. Plan to irrigate only small, highly visible areas and let Mother Nature do the rest. Soils differ in their ability to hold water. Amendments can be used to help soils hold water or drain better. More plants are killed each year from too much water than from drought.