Curly oaks are quite unusual and they are not recognised as a separate variety of oak, but rather a genetic quirk of our native oaks. Many trees (and plants) favour a form of growth called apical dominance. This is where growth is focused along the main stems and any lateral (side) shoots are inhibited. Curly oaks occur when the tree favours one-sided lateral growth rather than apical dominance (sideways growth from only one side). Over the years this leads to curly or twisted branches forming a Get Likes, Have You Ever, Double Exposure, Favours, Stems, Branches, Separate, Over The Years