Well I guess genetics plays a part in growth, so there's the nature part. If you have tall parents you're likely to be tall yourself. If your parents have dwarfism, chances are you may also end up with dwarfism by inheriting that gene.
On the other hand, diet and environment can be contributing factors to growth. Eating the right kinds of foods for example - calcium rich for bone development - can aid with growth. Being in a household where both parents smoke though could cause stunting of growth through passive smoking.