If you are trying to have maximum plants in your garden, the outer periphery of the house can also be used and made a part of the garden. Of course, the key concern would be a threat to the plants from cattle (assuming people are not a threat). There are certain plants which cattle do not eat. The Oleander, for instance, is not consumed by cattle. Among trees, the Indian Beech tree, popularly called Pungai in Tamil, is not touched by cattle. Any cactus-like plant would also be a safe bet to plant outside. The Parijat Tree(Nyctanthes arbor-tristis, also called Night-flowering Jasmine) which bears beautiful flowers that give off a very pleasant scent, is another good tree to plant outside. The Parijaat tree is revered by Hindus. It also has immense medicinal properties. The flower stem, which is a brilliant orange in colour, is used for cloth dyeing.
A word of caution here. While cattle do not eat these plants, they could trample on them(which is often the case near my house). One should build atleast a simple wooden fence to protect the crops.